If you follow Hello! Project posts on Twitter I’m sure you have also noticed tweets with these kind of fan art images. I think they are cool caricatures. You always know who’s that girl in each picture.
Man responsible to those drawings is comic artist and actor Takayuki Mizusina. He seem to be a Hello! Project fan as most of his J-pop related drawings are about H!P girls.
I think Mizusina’s most known works here in western world is comic book seria “Lovely Muco! – The happy and daily life of Muco and Komatsu san”.