When you send a screenshot (even if height/width only is cropped) , the screenshot’s width and height can be used to find the iPhone model of someone or narrowed down.

The most unique sized iPhone on the market right now is the iPhone 16 Pro and iPhone 16 Pro Max, as no other phone has the same width and height. So if you send a screenshot people will 100% know your exact phone. The regular iPhone 16 is common with the rest of the other phones and not unique.

If you send a screenshot from a iPhone XR, people can know if you using an iPhone 11 or iPhone XR since they have the same dimension which narrows down alot of options. (828x1792)

You can use this site here to view a list of all the dimensions. Click the iPhone’s tab and sort the physical width or height.

If you don’t want to expose your phone model, crop both width and height of each screenshot randomly. I would suggest cropping out the top of the phone as it shows your time if you care about that. Some sites like X have random inaccurate dimensions in uploaded screenshots, which is different from the original raw screenshot.

I haven’t really checked with android phones, but it’s probably the same thing.