Here's the refrigerant flow diagram:
The ejector is a MIG welding tip brazed into a tee. The extra TXVs are for the reduced pressure zone and vapor return. The ejector creates the reduced pressure zone, making good use of energy that is otherwise wasted. The two stage cooling enhances dehumidification. Since the refrigerant exiting the ejector has a lot of vapor, a phase separator and third TXV are used to allow some vapor to bypass the first stage evaporator, reducing the pressure drop across it.