Panel 1: As he and Michael stare out of the picture window, John asks him if he thinks that there's enough snow out there to ski on. This makes him a slightly better parent than the one who won't let Mike use the skis.
Panel 2: Mike says that he dunno; he did, however, tell Elizabeth to go out and measure it.
Panel 3: As we look at Liz looking at her feet and the dusting of snow on the ground, we find that Mike told her to stand there until it comes up to her knees.
Summary: Great. Another cruel and stupid sight gag at Liz's expense because she's too dim to know a mug's game when she's seeing it. Ah, well. It leads to John doing something reasonably intelligent and taking the people willing to take lessons to the slopes.