re·marque ri-ˈmärk. 1. : a drawn, etched, or incised scribble or sketch done on the margin [of a proof, print, or edition].
It's not about the size or how quickly it was done, regardless of how the hobby has bastardized the term (something we're apparently very good at it). What are so commonly being called remarques (or remarks) are frequently just convention sketches.
This is a gallery of remarques, so these are drawings done on other things and not meant to be a complete piece of art in and of itself.