It is not intuitive at all to me. From the article, I can see that there's some sort of penalty by having more billionaires in the country, and that somehow leads to "the time needed to earn $1 is 63 minutes in the US", which doesn't really line up with the fact that minimum wage per hour ranges from $7-$18 depending on the state.
The "old" way was to measure median net PPP per capita, which makes more sense to me:
https://upload.wikimedia.org/wikipedia/commons/8/85/Annual_m...
This time is a global average, including non working people or part time people.
The figure you linked to is particularly unintuitive. It shows income per household, divided by square root of household size. There are plenty of complex and unpredictable interactions with heuristics like that. For example, if housing becomes more affordable, young people may move out sooner. Then there will be more small households with low incomes, which may bring the reported income down.