I am going to assume the original comment-or simply didn't think about inflation (common mistake...which is further understandable since the graphic doesn't make it obvious whether or not it is nominal dollars or adjusted dollars).

So in that spirit, here is another resource which talks about minimum wage and even included an adjusted minimum wage graph within:

https://www.cnn.com/2021/02/21/politics/minimum-wage-inflati...

The minimum wage is not the only measurement for this discussion, but it does seem like since the 1980's the purchasing power represented by minimum wage has been falling (but at the very least is less today than then).

The graph is already adjusted for inflation, it’s in 2018 dollars. You can’t adjust it a second time.

Those numbers were already adjusted for inflation.