This is a very odd and un-McCaffrey story. I keep thinking it's a Zenna Henderson, actually. The small child with abilities that he thinks are perfectly normal and that none of the adults in his life notice at all (well, beyond thinking he's a bit odd) is very much a Zenna Henderson theme. McCaffrey presents a nice version of the idea though - Jeremy can make his art 'proper' and it becomes real (as in, an edible if a bit dry cookie, or a pastel horse that prances around until it 'brushes itself out of existence' against the wall). And then the question arises of what a 'proper' Santa Claus is... ( )