As Yaw said, you can have many different photos in a survey by having each photo created by a different question. I have had surveys with multiple photos in the past. I'm not sure where you are deploying the tool, but a few tips if you are capturing lots of photos:
- If you are doing daily uploading, the bandwidth upload requirement will be higher than ODK forms with no photos
- Using Briefcase to pull the data is very helpful to access all photos offline, and I've found Google Fusion tables to be helpful in 'visualizing' photos across geographic areas/topics/sectors
- Managing and naming thousands of photos can be tiresome, I used the trick I posted about HERE and it helps a lot.