At the top there are a couple of different tabs: "Overview" , "Submissions" , "Community" , "Screemshots" and "Submission feed". In the tab screenshots are a lot of - well screenshots but how do you upload them to this page or do they get there?
Good question... I want to know too?
When you edit your game page you have an "add screenshoot" button at the right, just below the cover image settings.
The jam page use the same screenshoots.
Okay thank you!