I believe that our group (Jed, Chance and I) are going to be doing an analysis of how GLaDOS treats Shell/the player and or the effect of game play on the player. This article addresses the sarcasm/jokes in the game, relationship between the player and the game, the humor it includes, and more.
The author also answered my question in an earlier comment:
"A computer offering a box with a pink heart on it to a prisoner is a nasty satire on how stupidly irrational human beings are. It's ruthless and condescending, and yet ten minutes later when, after some reluctant deliberation, I dumped the cube into the furnace GLaDOS reports that I destroyed it faster than any test subject ever."
I apparently was not the slowest in dropping the box; she just tells everyone this.