Did you want to see exactly how Autodesk Simulation Mechanical is interpreting your contact pairs? This is how!
Head over to the Draw tab on the Ribbon. In the Design Panel you should see Layer Control. Picking this will start a small dialog that controls the visibility of the layers in the current model.
Uncheck all but Layer 15. This contains the contact pair mesh. In the image above a large surface from each mating component was selected to define the contact. The result on Layer 15 shows how Simulation Mechanical interpreted that contact.