I think this is second time a character has written things that are depicted as hanging over his head. (I forgot exactly when the first was, unfortunately -- it's possible I'm getting confused and this is the first, this post has been a few days in coming.)
The convention is odd, and I think originates with Peanuts. It is hard to come up with new conventions that are still at-a-glance comprehensible to the reader. This one is helped by the fact that Charlie Brown is obvious writing, and the words hanging in the air are hand-written. Thought balloons had to have been a harder sell.
A hint that Charlie Brown doesn't get much for Christmas. This could be taken as another hint that his family is working-class; the first such hints were from Violet snobbishly lording it over him, and Shermy's huge train set contrasted with CB's tiny loop.
Once again, an early Peanuts strip presents a scene that wouldn't have been out of place in Calvin and Hobbes.
If you ever find a discarded calendar with December 17 circled in red, you'll have a pretty good idea who owned it. Schroeder's affection for the composer is alternatingly touching and worrying. I am reminded, for some reason, of that guy who left roses and cognac on Edgar Allen Poe's grave all those years.
To reveal that Santa travels around the world on a flying sleigh pulled by reindeer would be a let down.
That's a pretty harsh response, heh. I wonder if we can consider that it's Charlie Brown's parents who sent him that rejection slip, in order to manage their son's expectations for Christmas presents?
The blog has been updating sporadically lately because the blogging client I usually use, Blogsy (basically the only worthwhile iOS blogging client I've seen), was broken first by Apple and iOS 5, second by Google and WebAUTH 2.0, which hangs if you try to upload more than three images within a limited time. I hadn't noticed how slow the Blogger web interface workflow was until I was forced to go back to it for a while. Blogsy still isn't completely fixed yet, but at least it's useable again.
In more relevant news, the writer of Sally Forth (rather an underrated strip if you ask me) keeps a webcomic called Medium Large that referenced the Great Pumpkin yesterday. (Warning: language, NSFW)