It's very awkward to change/update an image. It can't be done straightforwardly on the image 'page'. Ideally there would be the ability to change the image there (whether that be because a better version is available, or metadata has been changed, etc.). In doing this the new image would retain the same name as the image being replaced, thus preserving any links to the image within profiles.
This would be akin to how Wikipedia now operates:
https://en.wikipedia.org/wiki/Wikipedia:Uploading_images#Reupload_existing_image
Right now you have to unlionk the existing image, which will eventually be deleted. You can upload the new image immediately, and get an image with a new name, or wait for the deletion and hope the new image gets assigned the old one's name. In the first case any links are broken.
