Reflections are beautiful to see—in still water, in windows, or mirrors.
If there are waves on the water, or leaves, or plants, or ice, the reflections might not be as clear. If a glass surface is wavy, or curved, or broken, the reflection will be distorted. Sometimes that's fun.

People "reflect on things," cognitively, mentally. The plainer one's mind and thoughts are, the easier it will be to reflect.
Looking back
photo by Orion Larson