I can download the .zip but I cannot expand it because it reports incorrect format. I would like Apple to build a system where I can download the screenshots so they can be read at a reasonable resolution - even one at a time would be a good start.

I also have this problem. I've been trying to download new screenshots and I can see the .zip linked file but after a long time it just times out. I cannot even download previous screenshots from a week ago. Also, make a system where I can select the screenshots and then download the entire package as one .zip file - not each individually.