You missed a couple important parts:

It defines living wage as enough no longer qualifying for food stamps.

Walmart has 3942 employees receiving food stamps. $6 million will get each one of them $1522.

You also missed this:

It says that to do this, Walmart would have to raise prices by about 1.4%.

Your numbers assumed that Walmart will simply lose $6 million of its current profits. But, increasing its profits by 1.4% first takes us to ~304 million. With the Walton family still taking their 294 million, that's a 10 million budget, not 6 million.

That is enough to give each and every worker collecting foodstamps another $2536/year.