Small UI issue

I have discovered a small UI issue. The issue is not changing game behaviour, but as a UI/UX designer, I notice stuff like this.

The issue happens when changing summoner spell icons. Whenever I change from an icon to another, the whole row of icons shift 1px (maybe even less) to the left or right, depending on which side I pick from. This doesn't happen to every Icon, but try and play around with it, and you will see it happen at occasions.