There were memes going around on TickTock a while back claiming Biden offered $300/hr jobs picking cotton, as a joke. Some people took it seriously.

There was also a separate argument on Reddit about it, saying it was such a shitty job that no-one would do it for even $200/hr. So someone made a poll about it. Which mostly seemed to show (going by the comments) that people didn’t understand cotton picking wasn’t a year-round job lol.

I think it's being presented by the teacher as an insensitive way to introduce that history. But the subtext is all the times black people have been lied to and fucked over in various ways. So the joke is that they're being lured back into the fields and will be re-enslaved, I guess. It's pretty dark, especially the way things have been going in the US. Idk, someone else might interpret it differently.