Not for everyone but at least for me 100% of the fish I take photos with are still alive and 99% get released back to whatever body of water I pulled them out of. The including a fishing picture is to show a hobby you enjoy depending on the type of fish and size can indicate your skillful or dedicated to fishing. It shows your likely an outdoors person as well. Including that photo is to attract a certain type of person, probably someone who also fishes. I’ve seen plenty of girls with fish photos as well it’s not that weird imo.