Due to the unpredictable screen size, in some places we've built in responsive and adaptive behaviour as the size changes.
The easy test to do is to simply shrink the VS Code window and see what happens. Toolbars should rearrange themselves into rows, large tiles should shrink into small tiles, and similar.
Look at all of the behaviour this toolbar exhibits as it gets smaller. Elements drop into another row, labels are removed to make space, etc.