If you cover up the current picture along the mirror lines, leaving just a sliver of a wedge, you can see (going backwards) a nearly full S, most of what looks like a K and the top of an R. Hypothesis - this is a red sign that ends with the letters "rks". There's only so many words that fit - "works" being an obvious one, "parks," "perks," "forks," "marks," etc being less likely but potential ones. The sign also appears to be outside based on colors but I wouldn't bet my trip on it. Unfortunately I can't remember any signs that fit this description in Epcot Future World and none are coming up in a quick list of shops and stores so I leave it to those who've been recently to fill in the rest of the puzzle.