The vapour from the vessel becomes the motive force (highest pressure)
The vapour exiting the evaporator enters the suction port (lowest pressure)
The combined flow leave the devices and enters the compressor.(medium pressure)

effectivly we have a 2 stage compression system.

The suction of the compressor would be higher than if it came just from the suction.

The compressor mass flow would increase (higher inlet pressure)

So the total system mass flow would increase, including increased liquid mass flow through the evaporator.

Carter Widget (simplified)