A big change is afoot at Walmart, and some shoppers are starting to notice.

It all comes down to one of the smallest (but most important) features of any store: price tags.

The retail giant's adoption of so-called digital shelf labels in place of traditional paper ones is causing a bit of confusion and concern about whether shoppers will get a fair deal.

Several lawmakers have filed bills to prevent the tech from being used for surveillance pricing or surge charging. A proposal in New York State would prohibit electronic shelf labels in stores altogether.

Walmart said in March that about half of its stores have the technology, and the remaining ones are expected to get it within the next year.

To learn more about these shelf labels and see how they behave in the wild, I visited two Wisconsin supercenters to talk to employees who are navigating the change.