I have an external monitor with a resolution of 2560x1440 pixels, and I noticed that the Applications list doesn’t fill the Activities zone, as seen in this capture:
There is a black margin around the icons.
Instead, if I switch to the laptop’s screen, which is 1920x1080, the screen is filled with the icons, as expected:
Is this a bug, and it should fill the screen with more icons in my bigger screen, or is it a feature, keeping the number of icons to a minimum to avoid “overdriving” the user?