the comment is a little confusing because it is not clear how the rotation is happening. You might say that resizeImageAndSave rotates if needed, and that if neither resize or rotate is needed, then it doesn't modify the blob at all.

If you had a config option to specify whether rotation was necessary or not, then you would know enough to be able to tell when you need to call this and when you can just share directly.  If you know you need to do this, and you know it is going to take some time, then you should at least put the hooks in place for displaying a spinner.