Turns out that once you add a picture to a site in Google Sites, you can’t delete it. Ever!
You can remove it from the page, but it’s still stored online. Found this out when I uploaded a pictures someone sent me that was over 2 Mb. I resized it to 100k and uploaded it again.
Apparently the official line is that you can’t delete things because Sites is a ‘collaborative tool’. This is BS, they just never implemented the functionality. So 2 Mb of the 500 Mb they give me is now gone for good.c