The splash lines around Charlie Brown's head are very effective. If I have occasion to draw a splash, I find I do it the same way. I probably picked that up from Peanuts.
Brutal honesty. More cartooning banter between Charlie Brown and Schroeder. What is it about Schroeder that makes him a good test audience for C.B.'s work? It might have to do with him being the mot artistically-developed of Schulz's personalities.
Turnabout. That is a very angry Snoopy there in panel three. On panel two though, in my experience deflating balloons don't go swish. Instead they make a noise that is charitably referred to as a raspberry. I wonder if this has to do with a change in balloon construction in the fifty-five years since this strip.
Unexpected honestly mixed with ignorance. This is the first time any of Schulz's characters has really engaged in writing. While the intellectual development of the characters is fluid depending on the needs of the strip, there does seem to be a sort of consistency to it. To my knowledge Schulz doesn't use Lucy for jokes about school reports, like he does for Peppermint Patty or Sally, which sort of implies the character is a good writer just from the absence of examples of her being bad at it.
And can't you just imagine Lucy writing a newspaper column? Probably "Diary of a Fussbudget" can be found on the Opinion page.
Another sight gag. More lines like the surprise lines in the first strip. Sometimes Snoopy is disdainful of being expected to perform dog-like activities, but sometimes he goes along with it.