Okay, the picture is of her husband being awarded the Dupont in genetics. The dead girl who is trying to 'connect' with Claire makes the picture fall to the floor as when Claire picks it up she finds the newspaper clipping which starts her search for the dead girl. Also, Claire actually saw her husband 'getting it on' with the dead girl in their house when she came home one night (but he didn't know that), but it was right before she had her accident so she subconsciously forgot about it. But the night when the Dupont award was being presented (the night when the picture was taken, which ties it back in again) was the last time the old lady saw her, Claire sees the dead girl in the audience and knows that she's the girl she caught with her husband, so she goes all pale and drops her glass. If you watch it again, look for the bit where she's in a red dress and holding the girls hair - the dead girl takes over her, and she seduces her husband - when he throws her off him, she starts saying everything that I've just mentioned, so you should get it then. Hope I've explained it okay ! :)