I'm pretty confused here. The graph implies unemployment is among the lowest it's been in decades? Is that right?

Also where does the discrepancy come from? That's a huge difference (5x!) with the official stat!

Is this actually measuring "underemployment", i.e. people who wish they were working full time but are stuck with some bullshit jobs? (And by bullshit I don't mean what Graeber means, but "this pays like crap and melts my brain but I can't find anything better.")