Yes, it’s different (two different icons) one a darker blue and the ‘a’ appears blurred and the other one (that you usually see first) more like a larger systray icon.

I never bothered with a desktop icon with 4.1, but the update to 4.5 put one there by default.

It’s cosmetic, hardly worth worrying about. I’m sure it will have no adverse effect and will be sorted eventually.