That'd be three separate and different descriptions per image. One in the alt-text. One redundant one under the image with no added value. And the long description
#nsfw
#sensitive
ImageALT tag ONLY if different than the short description.
You don't have to repeat what the text says in the meme.
But the alt text would need to be longer since it would need to explain what the meme is. The alt text and the short description would not be the same.
[image] (alt text = "An image about [topic]."
Basically, when you have super long descriptions (over 500 to 1000 characters), you should treat it as if you are promoting a blog post on social media (rather than the whole thing only exists on social media).
"I have no interest in your topic, and don't even read your posts, but you violated this rule that I arbitrarily made up, and I will force you to change even if your actual followers don't even want it."