Patty wears a travelling coat in this one, a decidedly 50s-ish touch.
This is the start of a minor running gag, the Peanuts kids often get candy or comics from this particular drug store, and the manager gets annoyed when they don't buy things. (Just think: Peanuts started back in the days when drug stores were still a suitable kid hang-out spot, and ended in the days of the Internet!)
