Choosing Whether A Given Background Image Is Made Vertical (and Cropped) on Mobile

Site URL: https://thetre.es

Hi there,

I'm sure this has been answered before, but can't find it.

I have lots of background images on my site, as one does in Squarespace

URL: https://thetre.es
Password: sassafras

I'm fine with some of these background images being modified when I'm the site is being viewed on mobile (typically they are made to be in portrait orientation with the sides cut off). But there are certain background images, when viewed on mobile, that I'd like to be displayed in landscape format with no sides cut off, as they are displayed when viewed on a desktop browser.

Is there CSS code I can use on an arbitrary background image to make this happen?

Thank you in advance!

Ted

PS: Screen grab example of an image that's getting the unfortunate portrait treatment.