It's a thin plastic board, usually about 7X10 inches. Often with drawings of various manga or anime (you can get all sorts of non-anime as well). They're meant to be used as a flat surface to put paper over and draw, but they're more usually used as collectors items nowadays.

Solarpunk is a movement focused on a positive, ecological vision for a future where technology is used for human-centric and ecocentric purposes. It is a literary, artistic and aesthetic sub-genre and is also closely tied to eco-political activism. Solarpunk narratives have a distinctly positive and utopian foundation in contrast to the often dystopian visions found within other "punk" science fiction genres.