Emerson Lake and Palmer’s Brain Salad Surgery cover is pretty iconic. Emerson was introduced to the artist, Hans R.Giger. In the anniversary CD they have some interviews, and Emerson talking about the artist, his home and the cover is interesting.
The woman is Giger’s wife, and the original artwork had her lips to a penis. The studio wouldn’t allow it, and Giger wouldn’t let them change it. Eventually they compromised and airbrushed the penis out with a shaft of light.
BSS by ELP was my first thought as well.