Are Image tags changed for WP compatibility?

When using HTML import 2, are the image size tags preserved or altered? I have many images with tags that reduce their size (for mobile pages). When I import, will they still display with the smaller size or will they be re-sized back to their actual dimensions?

I’m importing pages that were originally prepared only for mobile devices, and this meant smaller images. Now, the images need to be restored to their actual dimensions.