We have been on the MAGIC three times, but not the WONDER.
I imagine the photo ops are similar.
One picture is taking at embarkation.
At FORMAL NIGHT and SEMI-FORMAL NIGHT there were opportunities to have pictures taken in front of several different backdrops and/or with Mickey, Minnie or other characters.
There was a schedule of when the characters would be available and where.
Characters were available near the kiddy pool at specific times for photos.
There were some opportunities to have your picture taken with the Captain.
The photo shop is called SUTTERS on the MAGIC and that is where you could see your photos, decide if you wanted to buy them and pitch in a collection bin the ones you did not want to get. They had some stock pictures available of the ship in different locations also.
Basically, there are a lot of opportunities. There was a package deal also available and if we bought it but did not like that many pictures, we could get a pro-rated amount of money refunded.
If you want photos, you can get them. If you don't you are not obligated to buy them even though they were taken.
Hope that answers your questions.
Jan