Mobile design: When to use full-width images and when not to?

I am currently researching and trying to figure out any best practices regarding full-width images. On the site I am designing, we have used full-width images to showcase our products in their best light. However, I know certain design aspects like slightly rounding corners and making images not full-width can signify that they are clickable.

I have seen examples of images that are full-width and clickable, and images that are not full-width, with round corners, which are also clickable.

I want to establish a UI convention across the site, but am having trouble determining which method to go with. I know both methods can work, but is there any research or data supporting either way?