the.com/reflection pool

means A shallow, still basin of water designed to mirror a building, monument, or sky, turning architecture into its own doubled image.

from Straightforward compound English: 'reflection' from Latin 'reflectere' ('to bend back'), describing how light bounces back off a surface, joined to 'pool,' from Old English 'pōl,' a small body of still water. No myth needed — the name just describes the trick: still water acting as a mirror, a design idea long used in gardens and courtyards before becoming a fixture of grand civic and memorial architecture.