Which one?
On on the left is wheel. It "rotates" when you start driving.
One at the top center is ICE, internal combustion engine.
One on the right is hybrid battery.
When you drive, there will "energy stream" flowing from battery to wheel directly, from wheel to battery, or from ICE to wheel or from hybrid battery to ICE to wheel, when hybrid battery is helping ICE with high power demand.
Green READy means system is up and functional.