It's an inaccuracy about race AND it is discriminatory. Holy hell, how many straws must be grasped at before you get that it is racism and many other things too? It's ignorant AND racist. It is a generalization AND racist. It is many things AND racist, but there is absolutely no way you can say that it isn't racism without throwing every book on the subject out the window.
So, this person https://imgur.com/a/ecidy is black in the United States. They are white in Ghana. Race is a social construct. By bringing up their race in a generalizing way, this is definitively racism. Whether the generalization is intended to hurt or not does not matter. Well intended generalizations about race are still racist. Whether they knew it was bad or good is still racist. If it is a generalization or judgement involving nationality, ethnicity, or 'race' then it is racism. That is exactly what this is. There are tons of great books about the subject. I suggest The Meaning of Difference. It will teach you a lot. https://www.amazon.com/Meaning-Difference-Constructions-Orientation-Disability/dp/0078111641