The “real wages” is just the difference between the nominal wages and inflation. It’s negative when wages have increased but not as much as inflation, and positive when they’ve increased more than inflation.
So the literal number of dollars people are getting have been going up the whole time, but for a while there the amount of stuff your money could buy you was going down anyway. It’s recently the case that the amount of stuff you could buy has been going up. Not, you know, a lot, but…
It is worth noting that the article itself does bring employment rate into it, stating that the reason for the real wages spiking like that did in 2020 was the lower wage employees leaving work, thus raising the average wage.
I haven’t seen the data on employment rate, but if the bottom end of employees are still not back to being as employed as they were at the start of the pandemic, then that may be keeping average wages higher than they’d otherwise be