The windows in the restaurants at the All Star hotels have mullions like that, but I don't remember if they were deep enough to sit one of those hats on or not.
Looks to be frosted glass as well. ; So maybe the Windows to a gift shop or video arcade? brought to you by an (HTC) "Incredible" Guy.
We might be needing a hint along the way...at least narrowing it down to parks vs resorts, or which park. ; For now, I'll try...Backlot tour.