The jam apparently allows the participant to submit as many submissions as they like and the optional theme is "lost games for the Nokia 3410".

If there are multiple submissions, are they allowed to be related to one main submission? By "lost games for the Nokia 3410", does this mean any game mockup or specifically the games originally made for the Nokia 3410 back in the day?

Any game mockup is welcome and encouraged. 

The multiple submissions may be related.

Also, is adding a dithered photo and a faux copyright text allowed?

Will the participant be allowed to include their submission in their pixel art portfolio?

I just don't want to exploit any loopholes here.