。
Where did she get her photo taken, I wonder?
Literal
She [topic-は] photograph [object-を] where [at-で] had-taken [explanatory-の] [I wonder-だろう].
撮ってもらった (had it taken for her) uses ~てもらう for receiving the service of someone taking her photo. どこで (where) asks about the location. のだろう combines the explanatory の with だろう (I wonder) for a speculative question. The sentence wonders about a past event — where did the photo get taken?