imho, alt text needs to get the info density right.
<picture of dog>
"I'm bragging I own a dog again"
vs
"brown dog with spots on ears sitting in shadows from window. There are dirty cloths scattered around the floor. A corner of the couch got in the photo frame. My thumb is obstructing the top corner of the photo. The snake plants are blurry."*
* Also, this is full of $#!+ fully blind people can't related to.