Reflexus

A solitary man walks home carrying briefcase and a bag of groceries. It's evening. Close to home, someone in a hurry bumps into him, trips, drops photographs and runs off. The man continues home, opens a bottle of wine, and looks across the quad to an apartment where a woman drinks a glass of wine. He smiles in her direction and then watches in alarm as a man enters her apartment, looks at photographs she has hanging about, grapples with her and knocks her down. Our man rushes toward her flat, seeing her assailant flee. He dashes into her apartment, but there's no body in sight, just photographs hanging to dry. He looks at them. What's going on?