Whole Foods' kvass is not kvass. Can anyone explain?

I have seen signs that say kvass is coming soon to Whole Foods in New York. Some of the signs say "The Russians are coming!" and the like. I guess it is here, because the other day at Whole Foods they were giving out kvass samples. I tried it and it did not remotely resemble what I thought kvass was. I have been drinking kvass for years and my understanding was that it is sort of a yeasty rye soda from Russia. It is made out of bread and it bears some resemblance to beer. With the Russian-themed posters, I thought the WF kvass would be similar to what I get at Russian grocery stores in New York. However, what they were sampling at Whole Foods was a brightly-colored, non-carbonated, tart vegetable drink.

I tried googling and all I got were a few people also complaining that WF kvass is not kvass. Why is it called kvass, then?

Thanks for any insight!