It’s time once again for a Little Nemo card, the Raphael Tuck postcard series in which some unnamed artist simply copied a Winsor McCay panel as well as he was able. The game here is to find the strip that originally had this scene. Should be an easy one, we can see they’re in the ice palace, one of the most famous sequences of the strip.
This one is deceptive, as the artist took liberties with the original art. The image of Flip is definitely from 1906/06/03. But Nemo's outfit is the one he got on 1906/04/01 and had for a few weeks. The princess's outfit is from 1906/07/08.
https://www.comicstriplibrary.org/display/161
https://www.comicstriplibrary.org/display/188
https://www.comicstriplibrary.org/display/203
Ah, so it was deceptively simple. Nice job Brian!