Transcript:
Charlie Brown stands on the grass looking to his left. He exclaims,"You dog!"
He continues,"You cur!"
He continues,"Oh, you dog!"
Snoopy sits looking in his direction confused.
I don't get this one.
Yeah, tbh I'm kind of confused at this. It comes across as rather mean for Peanuts. Either Charlie Brown is saying those things to someone else out of frame and Snoopy is confused because he thinks Charlie Brown is talking to him, or Charlie Brown is mad at Snoopy and Snoopy doesn't understand what he's saying.
Related, I found out that there's a transcript available from the source so I'm going to include that going forward, but it doesn't clear things up either.
Could it be a commmentary on how dogs mainly listen to the tone of a humans voice, rather than the words?
There would be some meta humour in this interpretation, as Snoopy is later depicted as understanding, reading, and writing English perfectly, even though he doesn't speak.
For posts about the comic Peanuts, by Charles M. Schulz