These are shelves installed at the ends of cabinet rows. This creates more storage space via open shelving.
End shelves are not just functional by adding extra storage, but they can be decorate points of interest. Owners add end shelves if they are unable to add another full cabinet box in the same row. The end shelves usually match the finish of the cabinetry, but they can be a different color or texture in an accent color as an interior design choice.