When the shop first opened, the red and black Mickey design seen in the photo above was on the wall behind the cupcake designers.
This photo below is what the wall currently looks like:
Disney is widely known to be protective of their brand and they have very specific regulations on how the image of a Mickey head is to be recreated.
The article goes on to mention that the employees at Sprinkles had no comment on the issue.
News source/photo credit: Chip & Company