It’s a bit down on the product page.

The display is 7.5 inches.

I’ll update the description to make this more prominent.

Can you give me an idea of what a png/jpg would look like on one of these? I only see the calendar on the page...

It's a monochrome screen, pictures will probably need to be dithered to 800x480 1-bit, something like this:

https://www.crystalfontz.com/product/cfap640384a00750-640x38...