This is a really good video as it shows some innovative thinking about the Wing Chun dummy.
There are some arms added, which makes the practitioner re-consider footwork patterns.
Randy Williams talks about the 'V' shape footwork and how the 2 extra arms affect the drills / partner relationship.
Also, what I liked is that he kneels down to use the dummy. I have not seen anyone else do that before, as it makes you think about height-levels in a new way.
Some of the comments to the video think the extra arms could teach bad habits as you could be tempted to reach to the extra set of arms rather than step to them or pivot into them ?!
I think this is a good idea.