She's fully airborne, arms extended, one leg bent, the other pointed — this isn't a jump someone does once and gets lucky. It's a dance major's line, held mid-air, and it's the whole reason the shot exists. A stiff standing pose would've told you she went to USC. This tells you what she actually did there for four years.
The brick archway at Bovard Auditorium gives the frame its symmetry, dark shadow behind her making the white dress and red sash pop, the arch itself framing her like a stage would.
That's usually where Stanley starts with a session — not "what looks good," but what the person actually studied, did, or became known for, and building the shot around that instead of a generic graduation portrait.