AEG & the initial pump out...
The reason why the 'proper' AEG's pump out for a short time is to properly activate the 'Eco-lock' sump ball valve. The sump water is pumped up to a header tank (this is why the drain hose appears to be attached to the top of the machine).
When the pump stops, gravity allows the water to flow back down into the sump, forcing the ball-valve to be sealed against the tub base. The header tank principle allows a better 'back pressure' than can be achieved by simply using normal drain hoses (current Bosch, Hoover 'New Wave', etc).
This is also why you have to pour a litre of water into the machine when new, or after inspecting the pump filter.