The griddle was not electric. The plugs on the griddle interlocked the operation of the rear element with the thermostatic unit in front. Only the outer set of rings on the front 8" unit heated to even the heat input between front and back and the theory was that by the time the heat traveled to the thermostat in the center of the unit, the heat would have reached the edges of the griddle.
It was not uncommon at that time for 30" ranges to have only 1 8 inch element. We have the same stove in white. This is very much a transitional range for GE. It has new squared edge styling. The old, round clock with the complicated Timed Bake procedure was in its last year of use. GE would introduce the simplified clock, minute timer and separate start and stop dials by 1958.