It depends of the context. Here clearly we know the author didn't even tought about the idea of slavery. She just wanted to make a cute couple pose. I think you should not see racism everytime you see someone with dark skin being in a position of inferiority, because it will actually give a false image to the blm movement and all other anti-racism movements. Black people don't want to necessarily be in the superior position, they just want to be equal to a white person. Black people can also have a inferior/submissive position in fiction, as long as it's coherent with the context and not systematic just because they are black. So here, there's nothing wrong for the girl to sit on his lap, because it clearly doesn't have anything to do with racism. It's not good to see racism everywhere.
There's so many wrong with the front page where the dark girl is sitting on the white guy's lap... Idk why its like he bought her off from.the slavery market