It seems odd to me that the image gets distorted when the element is resized. Surely it’s a rare use case that one would actually want to display a distorted image.
Was it always this way? Perhaps I’m mistaken, but I thought images used to be “contained within” the element if the image aspect ratio didn’t match that of the containing element.
I’m wondering if this isn’t a bug - a regression from the way it used to work. 
EDIT: Not sure if I’m referring to a different issue, but I posted a suspected bug. I’d appreciate any comments.