Resizing a specific image for mobile

Site URL: https://falcon-avocado-k4w3.squarespace.com/

Hello!

I'm working on setting up a photography print shop site. Currently using the Palmera template (pw is "georgia").

I would like to reduce the size of one specific image at the top of the page, and reduce vertical padding as well (see attached images), so the first photo is peeking from the bottom of the screen.

I've tried this recommended way, but could not get it to work for me. Any ideas?

Thank you!

For graphics like this, I love Kerstin Martin's workaround. I use it all the time: https://kerstinmartin.com/blog/png

It preserves size across devices.