A smart approach is to activate PostUP early ideally when doors open rather than waiting until the moment you want to display it on the big board.
Early-arriving fans are often looking for something to do while they wait, making them great candidates to scan and submit photos. By getting PostUP running during the pre-game period, you can 'fill the tank' with approved content so that when you do put it up on the video board, you already have a healthy rotation of fan photos ready to display.
Your moderator can approve a batch of submissions, then step away and come back periodically to approve more throughout the game. This prevents the awkward situation of putting up a photo wall with only two or three images cycling.
The key is to start the PostUP instance so fans can scan in and sumbit photos, but hold off on displaying the mainboard output on the video board until you have a 'bank' of approved content. Once you have a playlist full of approved photos, you can go live on your video board.
The mobile moderation feature makes this even easier as anyone with the moderation QR code can approve photos from their phone during downtime.