Here is picture that shows part of the old Mr. Hooper's Emporium sign:
Image from Facebook
The image is undated, but based on the uniform of the Sesame Brass band member in the shot, it's likely from the late 1990s.
The sign shows Bert, Elmo, Grover, Cookie Monster and Oscar the Grouch. It's likely Big Bird and Ernie are far left just out of the shot.
Image from Google Street View
The store is still open, now with a sign that features Ernie, Bert, Elmo, Oscar, Zoe and Grover.