chance encounter
I was in a large downtown book store in the mid 70's, in the balcony. I notice someone walking in, and she lights up the place with her presence. She says hello to the clerk, and breezes back towards an office, out of sight. It lasted all of a few seconds.
WHO WAS THAT?!! I still had brain cells back then, and recalled that Sandy Dennis was in town for a play. THAT is star power. I hardly knew who she was, and just caught a glimpse of her from above, in a mostly empty store. And I've never forgotten that moment!