For students wishing to practice at home, here some resources to help. In the Chen style Tai Chi movement "Wave Hands like Clouds" (Yun Shou) this uses the double arm silk reeling movement with a side stepping action. The hands and arms rotate and move in a circular pattern and is likened to the weaving motion of a silk worm.
View the following youtube clip from 3.16 minutes to 3.30 minutes for an example of the movement looking from behind.
View the following youtube clip from 2.55 minutes.
The side stepping Chen style cloud hands movement, found in the short and long forms is based on the silk reeling foundation drill 'double arm front'. Visit the silk reeling pages below for more details.