Dan's hand keeps moving from on Serena's neck under her hair to on top of her hair when he's telling her he's worried about her after finding out about someone else taking the SATS for her.
In one scene, when Rufus and Jenny are sitting next to each other at the bench in the kitchen, Rufus is telling Jenny to call a date and cancel. When he places a phone on the table, the numbers are facing him, but when the shot changes to a close up of the phone, the numbers are facing Jenny.
Chuck calls Dan about Serena from a number that shows up on his phone as the Palace Hotel. But Chuck is calling from a cell phone, not a landline, so it should show up as his name or Serena's.