The second exercise starts with the hands being held in front at chest height but with palms up. The hand scissor together so they are on the centerline with (for example) the left hand over the right so that the right palm is in contact with the back of the left hand. The right thumb goes just below and between the knuckles for the little and ring fingers. Again, the right index finger does nothing. The other three fingers of the right hand hook around the far edge of the wrist (would be the medial part of the wrist normally but the hand is rotated so the medial edge is on the outside). Now the right thumb pushes the left hand so the left hand’s fingers are now pointed at your face. There is tension on the wrist. You then extend the hands outward to stretch the wrist. In both exercises it was stressed that both wrists are being worked.
A link to a short video