Testing kept surfacing the same problem: nobody could tell which aisle they were standing in, because the signage is above head height and out of view once you're in the aisle. Reusing the boards as targets solves the location problem with infrastructure the store already has.
The AR concept: the store's own overhead aisle boards are the tracking target. Already numbered, already lit, already in every aisle — no beacons or store fit-out needed.