Sophie's Twin

Once in awhile a cat outside will come and visit Sophie and Luigi. This morning, their little outdoor friend came by for a little visit. Lately we have been seeing a little black cat around, but this morning it was Sophie's twin. We have seen her around lots of times, but lately she seemed to have disappeared for awhile. Sophie and her "twin" will just stare at each other through the window. It is amazing how much they look alike. It almost looks like Sophie is looking at her image through a mirror. I wonder what they are thinking when they look at each other for such a long time?