reflective dramatic effect

He delivered his speech in front of the reflective pool in Washington D.C.

a cardbord box isn't reflective

A pool with a solar cover will absorb the heat faster during the day and when left on the pool over night it will prevent the loss of heat.

The verb reflect has the participles reflecting and reflected (both adjectives), as well as reflective (creating a reflection).

The noun reflection also has an adjective form reflectional (done by reflection or contemplation).

The adjectives have somewhat overlapping connotations. Examples:

reflecting telescope, reflecting pool

reflected light, reflected images

reflective tape, reflective film