iTunes 12.4 comes with a redesigned sidebar
With iTunes 12.4, Apple will make changes in the sidebar. They will change the way you select the categories.
Now, instead of little icons, there is a switcher. Furthermore, now there is a back button next to the switcher. However, other than that, everything is same.
iTunes 12.4 is entitled as a minor version of iTunes before the Apple WWDC, and it will be rolled out in a few weeks.