I'm not saying it was smart or appropriate, although that's entirely down to the fact that it's a 10ft poster of a bloke waving his schlong around IMO.
The original picture has been a meme popping up in most of my Whatsapp groups for about two years now. The whole point of the 'joke' is, "haha I made you look at a photo of a blokes massive todger," not, "haha, look at this silly black man!" Somebody has simply taken this and put Origi's face on it, presumably because of the nickname 'Big C*ck', which is just a pun on 'Divok'.