Heathcliff, master cartographer and wearer of sexy specs, is planning the best mode of attack for when the ice cream truck comes by the Nutmeg house later on that afternoon. While logic dictates that all you need to properly bushwhack the ice cream truck is a sharp rock tied to a stick and crackerjack timing, Heathcliff is using a compass and a map (probably cleverly titled "Map" like the one stuck to the wall behind him) to chart everything out, even though he knows when and where the ice cream truck will be. It probably works better than their Apple II sitting in the background.

Mrs. Nutmeg isn't at all worried that her cat is going to be leading her grandson into a fight against a two ton truck.