The Himalayan Art.org has got their information wrong.
While himalayanart.org is tainted by other mistakes, such as their anti-Shugden hatred, and anti-Gelug bias, in this particular case they seem to be correct.
This is not the 37 Deity mandala of Vajrayogini, it is the 62 Deity Heruka body mandala.
Both the inscription at the top of the thangka itself, and the ribbon inscription, explicitly state that this is a 37-deity Red Vajravarahi mandala from the Vajravali.
1. Vajrayogini's mandala is a double-tetrahedron, not the double-vajra palace of Heruka with colored wheels inside as featured in this image.
Some Vajrayogini/Red Vajravarahi mandalas are based on a double-vajra, rather than a double-tetrahedron, as one can see, besides the currently discussed mandala, here
http://www.himalayanart.org/items/88562 and here
www.himalayanart.org/items/69616 (top left), and probably here as well
www.himalayanart.org/items/58219Also, some are based on a single-tetrahedron, as seen here
http://www.himalayanart.org/items/58220 and here
http://www.himalayanart.org/items/582552. In Vajrayogini's mandala, the charnel grounds are inside the protection circle, whereas in this image, they are outside the protection circle as is the case in Heruka practice.
Some Vajrayogini/Red Vajravarahi mandalas have their charnel grounds outside the protection circle, or anyway not inside it, as seen, besides the currently discussed mandala, here
http://www.himalayanart.org/items/88562 and here
http://www.himalayanart.org/items/3313838 and here
http://www.himalayanart.org/items/3313839 and here
www.himalayanart.org/items/69616 (top left).
The aniconic mandala here discussed (
http://www.himalayanart.org/items/23376) seems to correspond exactly to this iconic mandala
http://www.himalayanart.org/items/58219 where the central figure is that of Red Vajravarahi with her characteristic boar face (many of them, to that effect), as well as to this
http://www.himalayanart.org/items/69616 (top left).
One might note that the general arrangement of the deities of the 37-deity Red Vajravarahi mandala is exactly the same as that as those of the 62-deity Heruka Chakrasamvara mandala, the latter's 62 deities becoming 37 if its 25 couples are counted as single deities, whence the similarity of shape, and the resulting confusion between both mandalas.