I'm sure that the news of the Norwegian women's handball team being fined for wearing shorts instead of the regulation (max 10cm) bikini bottoms has been covered elsewhere, but I've just seen this picture emerge and I think it perfectly encapsulates the differences between sex and gender.
It shows the male team next to the female team in their respective official uniforms.
Presumably, as these are the official teams, these are the top athletes in that field for each team. It's incredibly clear from the photo that the men's team consists of far taller and more muscular individuals than the women's (even though the women are all quite muscular).
There's the obvious sex difference right there.
And then, there's the uniforms. The women are required to wear tiny and revealing outfits (even when they object) that simply aren't applied to the men's team. And there's the gender.
If someone wanted to transfer from the female team to the male one, they'd be unlikely to qualify as they'd likely not be as powerful or tall as the men.
If someone wanted to transfer from the male team to the female one, they'd almost certainly qualify as they'd be more taller or more muscular than any of the female team.
And if the entire male team wanted to transfer to the female one (theoretically of course), then it's likely most of the existing female team would no longer qualify and there'd be no female team members across either team.
There'd just be two male teams, one of which wore bikini bottoms and one that wore shorts.
I really like this photo. I think it encapsulates the issues perfectly.