How do you make neighbouring loci feel distinct so images don't blur?

Vary their type, size, and position, and give each its own "scene" rather than lining up lookalikes.

Rather than five spots all on one shelf, spread them: a spot on the floor, one on the wall, one by the window, one on a chair, one at the door. Mixing furniture, fixtures, corners and heights gives each locus a different "feel", so when you walk the route the stations are unmistakable and the images stay put where you left them.