I'm sure this is exactly the case. I bet far more people interact (regardless of whether they 'like' it) with the swimwear/sexy pose shots than they do the photo of last night's dinner.
I like a lot of photos, but in my own 'explore' timeline I've noticed categories of photos that appear from time to time, despite me never liking them. Until I did the whole "I do not want to see content like this" thing and made them disappear, I was seeing a lot of fishing videos, or bizarrely, people slipping their feet into shoes filled with foam (?). I'm fairly certain that as you scroll down the explore timeline just paying over a playing video - or particularly opening something (even if it's really odd or gross) just because you're like "what the hell is that" seems to register it as interest. I think if that topic is pretty "niche" you start seeing it a lot more pretty quickly.
I guess a bit like reading a single story on Quora about going to prison, or surviving an aircrash - you can pretty much expect your daily digest to be full of those for the next 3 weeks.
Point being, I assume few people will admit to it, but I bet their eye is drawn to the scantily clad photo every time. They open it/pause on it - and it's probably registered as 'most interesting'.