Need custom CSS to stop image from rescaling to image block container

My image won't fit the container, it always wants to crop the edges out so you can only see it's full size if you click onto the lightbox. I need to be able to see the whole image at all times with no cropping and would like it to scale that way for all devices/screen sizes. I am using Brine template.

Here's the page with image so you can see for yourself: https://www.petticoatemporium.com/pitch-layout

I feel like I've tried everything but with no success! It seems so simple so it is so frustrating! Hope someone out there can help me!

Thanks,Zak