The copper lines in your attic are refrigerant lines for your air conditioning sysyem. "The small line moves liquid refrigerant from the indoor coil to the outdoor condenser and the larger line with the insulation on it moves gas to the indoor coil."
Yes, you are somewhat correct, if the system is a heat pump, operating in the heat cycle. However, operating in the fashion that you mentioned, the outdoor unit isn't the condenser. Condensing takes place in the indoor coil, during the heat cycle of a heat pump. If the coil in the picture is used for cooling (Evaporator). The refrigerant flow direction is different.