This photo clearly .......... the difference between the two brothers.

The correct phrase is "brings out." The complete sentence is: "This photo clearly brings out the difference between the two brothers." The phrasal verb "bring out" means to highlight, reveal, or make a particular quality or feature noticeable, which fits the context of showing distinctions

Why not others:

• Brings up means to raise a child or mention a topic.
• Brings in means to introduce or earn.
• Brings about means to cause, create, or lead to a specific result, change, or even