Even Microsoft uses iMac

Company loyalty in one pic

But hey i once went to a... Well i don't know what it was, but they had apple computers with windows all over the place

Looks like an unrelated space to me.
Why else would they turn the monitor at such an uncomfortable to use position at their work station?

One answer: asshole Apple fanboy trying to be a dickhead troll to people that look up at the sign.

Could be one of those apple parody stickers...