Proceeding from the assumption that it's fake (I have no idea), the things that strike me as odd are the squiggly panel borders and the modern proportions.
The borders are weird just because I can't recall seeing such a thing before, and I know that pulling a pen towards you makes vertical straight lines pretty easy.
The proportions of the people strike me as very odd, in that the anatomy looks simplified, but accurate. My (limited) understanding has always been that, apart from some special cases like da Vinci, artists drew things more in terms of emotional relevance, prior to the invention of the camera. And those exceptions were generally fascinated by detail, which this doesn't have. In that, it basically looks like a comic book, which is...weird, especially in contrast to the panels.
But, there are always going to be exceptions, so oddities aren't always evidence of a hoax, but I can see why someone looking at it might think something's suspicious.