Full width image widget

I’m creating a WordPress site for a friend:
https://www.chorltoncounselling.co.uk/blog/

The fourth widget down in the left hand sidebar contains an image with the same padding as the other widgets. I’d like to override that padding so the image can extend to the full width of the widget area (so the image is as large as possible) but it still needs to be responsive and change size according to the device. Should I use background-image? If so, where in the code should this be inserted? I want the background image to only apply to this particular widget and non of the others.

Apologies for the basic nature of the question. I did search the existing forums but couldn’t find an answer that applied. Any help would be much appreciated.

Thank you.

https://www.ads-software.com/plugins/genesis-featured-page-extras/