If Bash in that picture was incredibly fat, really gangly, or particularly ugly or even just appeared to be a manlet or something I'd get why Surtur was using his picture to troll him, but while I wouldn't say he is especially good-looking or in particularly great shape he looks perfectly normal. Not a porker, not really ugly, he looks fine. I don't pretend to know Bash's experience with women, but nothing in particularly about his looks in that picture would be a big hurdle to overcome when it comes to dating.
But you kids have fun with your trolling. 👆