(this is just an example; this can be reproduced on any quite very long article with some images in body)

Steps to Reproduce:

1. Open Wikipedia app
2. Open "Forth Bridge" article (https://pl.wikipedia.org/wiki/Forth_Bridge) switch to Polish OR open any long article that as at least one image close to the bottom
3. Scroll down to image showing bridge under construction
4. Tap it to open image full screen in app
5. Tap "Edit image description" and provide some / change existing description
6. After change to description is confirmed return to main article

Expected Results:

Article isn't scrolled in any way. Reader "lands" in exactly the same position as they were before changing image description and can continue reading.

Actual Results:

For "Forth Bridge" article, text is scrolled to reveal John Fowler's portrait (exactly this position: https://imgur.com/AER6C9j) even though you were editing you were editing a description for a different image. For any other article, text is scrolled up a random lines.

Based on this particular example I may try to estimate that it is scrolled up 20-25 lines, but that can be completely false shoot.

If article is short enough or if image was close to its beginning then article is scrolled up to the top, to article's title. If article was long enough or if image was close to its end then article is scrolled up to some random position in article.

Summary:

This may sound like a very cosmetic bug. It's not.

In fact it is very annoying one that can prevent / discourage many people from contribution to Wikipedia, by not changing / updating image descriptions.

I find myself very annoyed, when I am adding image descriptions to multiple images in a single article and after adding each and every next image, I have to manually scroll down article to "where I was" and manually remember / locate which image is already "done" and which in a serie still waits for its description to be reviewed or changed -- because I am always scrolled up, sometimes really far, far away from original position.

Often I find myself not willing to contribute anymore because I am tired of scrolling, scrolling and scrolling after each image edit.