vstol
As I recall from the article in Vertiflite, the craft was hovering in ground effect. The wings would significantly increase this hovering ability.
It is a beautiful looking craft, but like the previous Tiltrotor and the Tiltwing configurations, a high induced velocity thrust from a small disk area is needed during cruise and a low induced velocity from a large disk area is needed during hover.
Dave
Here is one way to get a 2:1 change in the disk area.
Tandem to Coaxial