After players have played, if you go to the hunt overview screen, you should see a Status button at the bottom of the screen. If you don’t try pulling down to refresh the hunt. From that button, you should be taken to a list of players, and from there, each player’s status. On that screen, you should see images they’ve taken. If you tap on an image, it will zoom out, and should provide you with an option to copy it to the camera roll.