"Mr. Pinky's Hefty Hideaway" is the place where the main character Tracy's mother, Edna, gets her makeover. This is also where Tracy is chosen to become a spokesperson. This is the setting of the only scene Mr. Pinky is in, besides the clip of him reacting to Interracial dancing on the "Corny Collins Show" breaking out.
This building is also most likely building 618 of the block, hence the number written right after the name.
Mr. Pinky's Hefty Hideaway might also be a plus - size dressing shop.
This is also the place where one of "Hairspray"'s hits was taken place, "Welcome To the 60's", performed by Nikki Blonsky and John Travolta in the 2007 movie.