I just verified the following works on my iPad:
- Select a person
- If necessary swipe from the right edge to open the info section for that person
- Select Gallery at the bottom right
- The Photo section of the gallery should be at the top. If there are no photos already attached the "Add Photo" button should be at the top. If photos are attached the button is below the existing photos.
- You should then get a popup that asks if you want to take a photo or choose an existing photo.
If that doesn't work can you describe in more detail what you are seeing?