The throne is the seat of consciousness at the center, and the sea of glass spread before it is the mind grown perfectly still, water no longer churned by emotion so that it lies clear as crystal and reflects the light without distortion. A calmed inner sea is the condition in which the higher self can be seen at all.
The number 4 marks the 4 elements and directions of the physical body, and the beasts are the 4 base forces of the flesh gathered around the center, now covered with eyes before and behind. Eyes everywhere mean these once-blind animal energies have become full of awareness, the raw powers of the body turned into instruments of total perception that see in every direction at once.
Throne: the central seat of consciousness within the body
Sea of glass like crystal: the mind grown perfectly still, reflecting the light without distortion
The number 4: the 4 elements and directions of the physical body
4 beasts full of eyes: the base forces of the flesh made fully conscious, aware in every direction