In 1793 Blake came forth with For the Children, Gates of Paradise; 25 years later he produced For the Sexes, Gates of Paradise. The second production has additional textual material and two additional pictures.
What follows here will be primarily about Digby's explanatory notes:
The Frontispiece shows two figures on two leaves: a caterpillar is eating one, and a human like infant wrapped in a cocoon lies cradled in the other one. What is Blake saying?
The first figure represents a worm of 60 winters creeping on the dusky ground (Tiriel, 8.11, E 285), which is to say a person who goes through life with no spiritual consciousness, a purely material animal living a natural life and eating only what he can get from nature.
Beneath the Picture:
"What is Man
The Suns Light when he unfolds it
Depends on the Organ that beholds it"
And this from Jerusalem (Plate 30 Lines 56-8 E177):
"If the Perceptive Organs close: their Objects seem to close also:
Consider this O mortal Man! O worm of sixty winters said Los
Consider Sexual Organization & hide thee in the dust."
The caterpillar represents this deadly dull man living without any spiritual consciousness.
The contrasting 'infant' figure in turn represents the endless possibilities of the new born.
We have a stark either-or: one has learned to eat the heavenly manna or not. Digby displayed two contrasting pictures: the first generally called Glad Day and the other "a worm seventy inches long" (not available except in Digby's book). It shows an old man with a long scraggly white beard looking at himself in a mirror.
That's the difference between people with a spiritual consciousness and others. (Could you perhaps see yourself as somewhere between these two extremes?)