I've been thinking about this recently, seen a ton of overton window memes along these lines

but I've also heard good arguments stating the opposite, that the overton window shifted the other way, and images like his above
is it just both sides saying "no u," or do both interpretations sort of work out?
like if you shift the window to the right, it does create a longer tail on the left
or if people radicalize left, they look at where they once stood and say "wow I used to be so much closer to the right, the window's way over there and I'm supposedly too far left now, things have gotten so much worse"
It's misleading and classic data manipulation. The marker for Conservative stays in the same place, but it's also further away from "center". And then there's the scale changing. I get that he's saying Liberals are further left, but is he saying Conservatives are further right as well? Whatever point he's trying to make is too muddled by the shittiness of the graphic. He thinks he's PBF but he's worse at memes than a senate Democrat, and that's saying something.
he's saying that the growth of extreme leftist views has recontextualized where the center is located, even though everyone else didn't significantly change their worldviews
one example might be the idea that hiring the most qualified candidate for a job regardless of race or gender used to be seen as a left-leaning position, but now it's a right wing dogwhistle because "everyone knows" that hiring practices aren't colorblind so you still end up hiring whites, and the current left position is that the best way to correct the imbalance to hire a quota of other races, even if a white candidate seems more qualified
so if you still believe you should make a genuine effort to hire the best person suited to a job, you are now espousing a bigoted right wing view rather than a left one