MacOS Design Review
These are the issues I found with Books.

Extra text added to clipboard

If you copy more than three words to the clipboard, Books will add quotes around them and append “Excerpt From” text. This behaviour cannot be turned off.

Here’s what happened when I tried to paste an example from a book about shell scripting into the terminal:

This is the worst misfeature in Books. Instead of just letting you copy and paste, it makes an incredibly narrow assumption about why you’re copying and pasting, and feels so justified in its assessment that it breaks a general-purpose, system-wide feature, making it unusable for any other task.

Unusual text selection

Throughout MacOS, you can select text and then either choose something to do with it from the menu bar, or right-click to pop up a context menu.

Books sees fit to break this pattern. Unlike every other Mac app, selecting any text in Books automatically opens the context menu. If you wanted to do something else with the text, like use the menu-bar or a keyboard shortcut, or drag it somewhere, you can’t do any of that without first clicking to dismiss the context menu. If you’re used to “select, Cmd+C” to copy, it won’t work. You must use the mouse to choose “Copy” from the context menu instead, because Cmd+C won’t work while it’s open. The computer skills you’ve learned in the rest of MacOS do not apply in Books.

The surprises continue. In MacOS, double-clicking a word selects it. (Triple-clicking selects the whole paragraph.) In Books, this behaviour is different. Although double-clicking a word in Books does select it, Books will then wait half a second and pop up the “definition” window as if you had used the “Look Up” feature. If a definition is found, Books will deselect your selection. If not, the selection will remain intact.

The bizarre thing about this is that there’s already a system-wide gesture to look things up. You can choose in System Preferences whether you want it to be “force-click with one finger” or “tap with three fingers”. But Books has decided that, no, this feature belongs on double-click, replacing the “select word” feature that you’ve come to expect if you use the rest of the OS.

Worse, if you use this standard gesture for “Look Up” inside Books, it only works sometimes. If you use it on any word in the first paragraph on a page, it doesn’t respond at all.

Lastly, when you look something up with the double-click method, the yellow box around the word you’re looking up will be missing.

Using the standard Mac “Look Up” gesture
Using the Books double-click gesture

The context menu

In most of MacOS, when you select some text, “Look Up” is at the top of the context menu, so over time you learn to expect it to be there.

In Books, “Look Up” is not even in the menu — it’s been moved to a submenu. It’s as if Apple has decided that “Look Up” is very useful, except when reading a book. Or, more likely, the same person who shoehorned “Look Up” onto double-click then considered the menu item superfluous and stashed it away out of sight.

Limit the use of submenus. Every submenu adds a layer of complexity and hides menu items from the user. Reserve submenus for when you have groups of closely related commands that can be intuitively grouped under a single parent menu item, or when you need to reduce the length of your menus.
Human Interface Guidelines

The submenu is silly anyway, because there are only four items in the menu: Highlight, Add Note, Copy, and the submenu. Most of this stuff could have gone in the top-level menu. Also, Mail, Messages and Notes are normally found in a submenu named “Share”, because that’s what you’re doing with them. “Messages” doesn’t make sense as an action. “Share → Messages” does. But Books just stuffs them under “More”. “More → Messages”. It’s not literate.

Fonts and styles

You can’t choose a font to read your books in. You may pick between four colour schemes. You may not define your own colour scheme.

The incredible disappearing title bar

The Books title bar is hidden by default, appearing when you hover near the top of the window.

Strangely, when the bar appears, although the buttons and text on it fade in smoothly, the bar itself has no animation and just appears instantly, so when you move your mouse past that area, you still see the bar flicker on and off, which is what the smooth fading was presumably supposed to prevent. Fade the whole bar, or pop it in. Those are both reasonable design decisions. This half-and-half approach is just sloppy.

Non-standard toolbar

The toolbar items themselves have their own special-snowflake designs, resembling neither the big colourful icons of yesteryear nor Apple’s new white pill icons. Whereas standard MacOS toolbars let the user choose whether to see icons, text or both, the toolbar in Books mandates mystery-meat icons only. Descriptions can only be shown by hovering over each button and waiting for the tooltip.

Old style
New style
Books style

Speaking of the tooltips, they too are inconsistent: the Notes button says “Show notes” while the contents button opts for the more voluble “Click to show the table of contents”. The full stops are also out of place, as other Mac apps don’t tend to use them in their tooltips, as per the HIG.

Use sentence fragments with sentence-style capitalization. This style emphasizes brevity and tends to be more friendly, which connects well with users in need of assistance. If the tag text must form a complete sentence, use appropriate ending punctuation.
Human Interface Guidelines

It’s minor stuff, but Apple’s older apps all take pride in getting the details right. The newer apps like Books just come off like they aren’t bothered.

Book Store and Library

So far we’ve only covered the reader window itself. Books also offers a Book Store and a Library. Weirdly, they share a window — that is, a button in the Library window turns it into the Book Store window, and a button in the Book Store window turns it into the Library window. Each book you’re reading gets its own window, unless it’s a PDF — those just get punted to Preview.

The Library UI itself is an iTunes-style mess of sloppy design like this:

I’d like to sort by “Show Title & Author”, please.

Perhaps the biggest mix-up is the selector in the middle of the toolbar:

What on earth is “List” doing there? It’s just “All Books” but displayed as a list rather than icons. Choosing between list and icon display should be separate from choosing which books you want to look at.