There are four Flip Flop circuits on the board, each circuit stores a bit, 0 or 1.
KDF9 words were 48bits, so it would take 12 of these boards to store one word.
The circular cans are transistors,
pale blue cylinders are resistors,
brown oblong components are capacitors,
and small transparent cylinders are diodes.
The circular rings with three windings protected by a rubber sleeve are inductances.