When Roseanne arrives at Mark's apt, he answers the door with a cigarette in his right hand.
He then sits on the couch and puts the cigarette on the coffee table. As Roseanne is leaving Mark's apt, and standing at the door, Mark gets up from the couch and leaves his cigarette on the coffee table. While standing at the door with Roseanne, his hands are empty, but as he closes the door, he once again has a cigarette in his right hand.
When Roseanne starts Dan's motorcycle, the engine revs several times but the sound does not align with Roseanne moving the throttle with her right hand.