Yes it does. And Optima say different things depending on the winding length of the strings. The sets are “pure nickel” but the individual short, medium, super long strings are described as “chromnickel”It's right below where your screen capture ends - under "single strings from this set": in the description for each of them, it does say "Chromnickel" (sic), as @tom-g pointed out.
...And yes, it also says "Reinnickel" / "Pure Nickel" (and therein lies the problem, as you pointed out).
