I think they would have seen their reflection in a pond or a river.So,because of anxiety they would have used some metals and glass to create a mirror.
Water was the first mirror. People saw their faces reflected in ponds and rivers. Another early mirror was a shiny black stone called obsidian. But these didn't give a clear reflection. When people learnt how to polish metal to a shiny surface, they used bronze mirrors.
Mirrors today are made of glass coated with silver. In 1508, glass makers of Venice, Italy invented a mirror made of glass. They coated the back of a sheet of glass with tin and mercury, which made it shiny and reflected images perfectly.
