Issue: If the markdown for an image attachment contains both defined width/height as well as thumbnail, the thumbnail seems to be stretched and appears blurry within the UI.

Example 1.) With "thumbnail": |width=362,height=192,thumbnail

Example 2.) Without "thumbnail": |width=362,height=192

Notes: Users can do this manually in text mode, but also Jira will do this if you insert the attachment into the description or a comment and then resize it by clicking and dragging - causing the blurry image due to not removing the thumbnail markdown.

Steps to reproduce:

1. Attach image to the case. Method does not matter.
2. Add the attachment to the description or comment.
3. In text mode, define the width and height of the image as well as thumbnail OR highlight the image and then click and drag the corners to resize it. (Example 1 above)
4. Save the description or comment.
5. Observe the blurry image.

Expected: Image would appear clear instead of blurry due to including the thumbnail markdown

Actual: Image is stretched/blurry.

Workaround: Remove thumbnail from markdown in edit mode when manually resizing images. (Example 2 above)