User blog comment:SEOkitten/The Importance of Images/@comment-4129195-20151026232606

Still wish Special:MultipleUpload would get extensions so you can add descriptions to individual files. I rely on it much (and I can guarantee others do as well), adding descriptions to individual file pages too long and tedious to do.

I do have a question: which image has a higher priority to show on SEO? .png, .svg. gif etc. or do they have an equal priority?