that contrast is hilarious.
Harry shows up and he's obviously Harry. Then Hagrid. Then Ron. Character after character flashes past, each recognizable as themselves. You start to get a little glimpse of hope.
Then BAM, brown Hermione, then BAM, black Snape. Gotcha!
Whats telling is the sequence. They know exactly what they're doing. They build it up, step by step, to maximize the surprise. Youre meant to be shocked by the contrast because if youre a "progressive" you get some kind of gay little thrill at being so brave and shocking and oooh wont this make the racists mad! And if you're a normal person well obviously you're like "hey thats fucked up, what happened?" and now you're a racist. So everyone gets some kind of reaction and engages with the ad at least a little.
I will give them this - after a few decades of this they are getting good at it.