The longer version adds in a scene from the night before the party, and finds Abra playing the piano before her parents come in to tell her that it’s bedtime.
Abra is playing it in her dreams.
After they tuck the tiny psychic in, David and Lucy hear the same song she was playing downstairs, but after investigating they are surprised to discover that the piano is playing itself a.k.a.
In Doctor Sleep’s theatrical cut, Abra’s big entrance comes during her birthday party when she shocks her parents by getting all of the spoons in the kitchen to levitate against the ceiling, but the Director’s Cut shows that episode wasn’t the first time that the young girl freaked out her parents, David and Lucy, with her abilities.