. . . from the linked article it looks like those are gross figures and not adjusted for purchasing power.
The article compares prices in the eurozone. I'm not sure that purchasing power has any relevance in this context.
Purchasing power is a concept used to compare the relative value of currencies by comparing what can be bought with each currency.
For example, suppose a basket of consumer goods and services can be bought in the US for $100, and in euroland the same basked costs €120. Ifd a US person going to euroland is to have the same purchasing power in euroland as they have at home (and vice versa), $1 should buy $1.20; €1.20 is the purchasing power parity (PPP) exchange rate.
If, in fact, $1 will only buy €1.10 then the dollar is undervalued according to PPP.
You can use the concept to compare living standards by adjusting GDP figures, houshold income figures or whatever by reference to the PPP exchange rate. (You can also use it as a tool to predict exchange rate movements if you think that currencies do, in fact, tend to trade at PPP rates, but not everybody does think that.)
But in this case all the places being compared are in euroland, and all the prices are in euros, so the purchasing power of different currencies doesn't enter into the question at all.