After the forward bend the sequence flows into Chair Pose on the way up to standing. A much safer and healthier transition than coming straight up in one large motion from the forward bend.
Warrior 2 is repeated in this sequence. It is quite often
nice to repeat poses during a flow. Adding certain poses at certain times helps transitions into other postures. So repeating a pose is often needed for smoother transitions. In this case it's done to create large sweeping motions.
Look at the back bend in the beginning when the arms stretch up.
It is a little deep. This usually aggravates the back unless you are really warmed up. Do not bend
back backwards if you have a back condition or degeneration to discs.
From the back of the knees push down through the calf muscles. At the same time from the back of the knees lengthen upwards through the hips. Turning the tailbone upwards help to lengthen the hamstrings at the back of the legs and allows you to feel this upward force. This way energy and mind awareness travel in 2 directions.