@kalmor I'm still new to writing image descriptions myself, but from what I understand the context that dictates what you should focus on when writing image descriptions
if it's a selfie, something like
"a picture of myself, smiling towards the camera, wearing a blue dress"
is usually fine
short and simple is best, with any (relevant) text in the image being written down as well
https://uxdesign.cc/how-to-write-an-image-description-2f30d3bf5546
this article does an excellent job of explaining different examples