To appear on the newspaper, would mean something like some magician waved his wand and they appeared standing on top of the paper. Does this more likely mean that they appear "in" the paper, meaning there is an article about them?
It sounds weird in Romanian as well, precisely for the same reason.
We've been told elsewhere in the course that "in" is the correct word in Romanian
Yep, in, not on. Now let's all move on.
This should be appear in the newspaper, not on. You appear "on" the TV however.
We can sit on the newspaper.