Egypt is both Mediterranean and African though, and Egypt had long been influenced by other cultures, commuities, and networks and trades long before the Ptolemies. These communities never existed in vacuums. And while yes, Cleopatra's family was Greek/Macedonian in origin, you have to also consider the scope of the time. We're talking three hundred of year between Alexander becoming pharaoh and Cleopatra dying. At this point the family was also Egyptian. Even though Europeans forcefully took control of the Americas we wouldn't say that Tom Englishman who's family came to the Americas 300 years ago is English, not American.

And as Bentresh has already pointed out, you cannot judge by the appearances in the art as to whether those people had Greek origins or not. These things, as is often the case, are more complicated than they appear.