Do you mean an 'astral being' of some sort ? Also , are you sure you have not confused symbol with image ?
But then again, you say you are already satisfied.
For those that aren't :
The image was derived from ' Mut - em - menu ' - a 'Lady of the Collage of the God Amen Ra at Thebes' Farr made that contact through the sarcophagus fragment in the British Museum
The 'Sphere' (in one of its functions) would be formed around the astral image of this 'Lady' by 12 members representing the zodiac and projected into this eidolon images of GD star maps and Kabbalah, (see, the GD Tree of Life projected onto the Celestial Sphere paper ) to invoke progress, growth and unification (presumably of the Order ? )
I am not familiar with this being a 'symbol' but more an image of Mutenmenu.
Horniman saw it as an 'evil force'.
What you were seeking, I believe is not a symbol as such but an image or eidolon. The building up of God Forms were part of GD practice but this form is not identified as a God, but a human - hence eidolon - and perhaps the reason Horniman didnt approve ?
(it cant wholly have been the practice, as Horniman had contact with a higher plane adept 'The Purple Adept' ... or it was more 'politically' motivated ? Soon they were popping off contacts all over the place, eg. Felkin's 'Masters of the Sun' who he wrote letters to.