As I think of it more, to depict the HP as a vagina is almost a chauvinistic depiction. To depict any woman as a vagina would seem that to me.
This process of birth is what springs into my mind when I think of the HP depicted in the Karma Tarot as the vagina.
I think the take on the Vagina as only a sexual part of physicality denies it's other (most important and creative) role as the entranceway to birth. What more ultimately creative act is the act of giving birth? The vagina is ultimate feminine/creative symbolism (as those ladies with their mirrors were to discover!)
The HP is about creativity in the material realm being linked with spirit from behind the veil.
The source of what we create is drawn from the ethers and through the veil and out into the material world. The link is not well known and not obvious hence the great secret of the High priestess is this.
The HP is often depicted looking very mysterious. The new take on the HP as the vagina, is far more obvious and in your face (unfortunately the meaning of the vagina synonymous with being of the 'lesser sex' is still around which totally negates it's interpretation as to being about creation in the here and now) No expression of physicality states this as openly as the vagina does in it's action and role. (but are the facts any less valid or important if displayed by the red-living vagina and not hidden behind the pale face,demure & mysterious smile and close guardianship of the traditional High Priestess.
The Vagina is so ulitmately a conduit for creative acts, that the meaning is bared and stripped in the karmaTarot version of the HP. Yet in the Karma Tarot, there is still the prescence of a veil for the powerful process of creativity is always subtle. The veil is coloured blue as in the traditional HP where it is a woman dressed in blue -usually a women depicted in a blue dress is symbolic of the Virgin Mary. Blue is also the colour of the feminine, the colour of distance, spirituality and calm. The perfect colour for the veil to have.