I tried it. You have to click on each photo you want to import. Maximum 100 photos, but you can "re-upload" the zip file and click on another batch of 100 photo

I tried it. You have to click on each photo you want to import. Maximum 100 photos, but you can "re-upload" the zip file and click on another batch of 100 photos. Then they are processing for a long time (which is understandable). The next morning — nothing happened, import disappeared, photos didn't appear.