Lobby photos at character meals are filed into a unique photopass number. The photogs will not accept your personal regular photopass cards to scan. They started selling a product called Photopass+ and it sounds like if you're holding one of those cards, you can have the photopass photog scan it in.
At CRT and Akershus, the lobby photo package with Cindy and Belle are included in the price of dining so you can have access to all the pics the Photopass photog takes and not just the ones they print out for you. When you receive the photo package, ask the CM who brings them to you about the photopass number for your set of pics and he/she will show you where the number is. I've received them in two formats. One was imprinted on the edge of one of the photos. Another was in the form of a printed out receipt. Once you get that number, you can log on to your online Photopass account and add the numbers to your account to gain access.
For places like Chef Mickey's or Tusker House where the lobby photos are not included in your dining price, you can get Photopass access to them only once you purchase the package.
Hope that helps!