Sizing pic differently on different browsers

Is there a way to make the featured image on a page stay put? I’m currently running the Rosa theme. Every time I upload a pic as the featured image it looks great on one computer but when I switch over to another it looks different and is showing different parts of the picture.

Example: One of the pages on my webpage is for a store. I upload a pic of the front of the store and the pic on my laptop shows the entire front, sign at the top and concrete beneath it included. When I go look at it on my desktop computer it cuts off the entire top half of the store.

I’ve been told it’s not possible to make the pic automatically stretch to fit the space, but can I set some kind of side margins? I’m new to any sort of website designing and messing with all the options hasn’t worked so far.

Thanks for all your help!