Actually, it's a reprint from 22 December 1980:
Panel 1: As he and Michael put on their winter gear, Lawrence says "Boy! Your mom's sure nice to take us to see Santa!"
Panel 2: He then asks Mike, who's putting on a hat, "But I thought you already went....how come you're going again?"
Panel 3: Mike says that he doesn't think that Santa got his whole list the first time.
Summary: What we're looking at, of course, is the start of an Aesop about the evils of materialism which will culminate in Michael* calling his teacher a nut for saying to not be greedy this Christmas; given that the Pattersons are, by nature, filled with bug-eyed greed, the hypocrisy is somewhat appalling.
(* Who, as we know, is someone with a bottomless sense of entitlement with a penchant for assigning his sister cruel nicknames out of wanton malice and who will, twenty-odd years later, leave his family to shiver on a rickety fire escape to rescue a laptop, the dick.)