Participants claim a tripcode preferably just for this challenge and post their image with it, also add a caption - no description. With the tripcode only participants each are asked to up-vote 5 foreign images at max. Participants are not allowed to participate with several images or exchange the posted one. The challenge is limited to 25 participants images, it ends about 48 hours after the last participating image-post where the votes at this time define the winners.
For images there are no further restrictions in addition to the /p/ ettiqette. The up-voters decide according to their own expectations, for example if they allow or disallow composings, aim for present emotions, technical correctness, graphical/structural elements and so forth.

Be polite and fair, also just bump this thread for your personal interest.