Just because water is wet, does not mean you aren't getting soaked. Hmm, that's not how that works.
Anyway, just a fun little caption, and since it's sort of a POV image without a face, nor with any names in it, you can pretend that you are just as clueless as the protagonist!
I have done many captions that involve showers and I think I know why they work well, both as a creator, and also a consumer of TG content. Bathrooms are usually pretty solitary and personal. Other than the possible dangers involved, it's probably considered a safe space. Women will use public bathrooms to regroup, fix up makeup or hair, etc .. and it's wear we do most of our grooming as well.
So when we see a caption with the plot inside of a bathroom; it's comfortable, but also a bit intrusive since it's supposed to be off limits to anything else. When something happens, it interrupts our comfort zone. I think that's one of the reasons why the shower scene in Psycho still remains an indelible image today, over 64 years later .. or why the swimming pool / bathroom scene in Fast Times at Ridgemont High is so funny and iconic as well.
And along with all that, bathrooms are often still gendered .. whether in public (though that's slowly shifting) or in a dwelling. I know a few people that has a "wife" bathroom and a "hubby" bathroom. And most other couples have bins for guy stuff and shelves and racks for the lady accoutrements.
It's familiar to everyone .. as everyone shits, and everyone bathes. It's a universal trope and understanding.
Hope you had a great week, and that the first week of Fall / Autumn finds you in great spirits!