If you are talking about the “Secret Love” clip from the old hit parade show of 1954, a note with it says that it is probably Ruth Berman – here’s a link to the clip
And her hand position would only come close to something correct if she had been playing on a wire strung Celtic harp. Thumbs completely down and fingers like claws. She did move in time with the music, but what she was doing would not have produced those notes. At one point she was plaing a gliss, but the harp was playing an arpeggio run.
It’s obviously an actress faking it. I don’t know who the real harpist is. Many students of Salzedo’s and Grandjany’s were active in those days. Pearl Chertok played for the CBS orchestra, as I recall, and Lucile Lawrence did ABC, I think, as well as the Firestone show. It was lucrative work.