Yeah, the commenter considers himself a legend, but he doesn't get the joke in the image. It's funny because his comment is unexpected as a response to the original poster's caption.
yes, that's clear, but who the hell are those people, what is the context, why is this in any way relatable to a man holding a trophy next to the woman holding a trophy, did he come in second, is that the gag, we don't know these people
Winner of UEFA player of the year (football award).
Man- Erling Haaland
Woman- Aitana Bonmat
What you're supposed to understand idk.
But I'd assume it's a sex joke, it's always a sex joke. Or maybe there's not supposed to be anything to understand in which case 'only legends will understand' followed by noone understanding would imply the reader not being a legend and hence a roast.