In an article on FengShui-tips.org, it states,"If it's done correctly the power of mirrors symbolically double your wealth, health, and happiness", and "Anything your mirror reflects it will double that." If you are trying to add space to your store, mirrors can help with that.
By using mirrors in display cases, you are focusing on the products reflected from them. Diamonds can look larger or more brilliant, make-up can look more colorful, and sequined products can look more dazzling and shiny.
Mirrors can also make customers stop to look at themselves. Placement of items near those mirrors can draw them to a possible impulse buy. If the display has things the customer can try on like hats, jewelry, or shoes, the odds are greater for a customer sale because they don't have to go looking for a mirror to see what the item will look like on them. Everything is right at their fingertips.
One of the most beneficial uses for mirrors is as a shoplifting deterrent. Mirrors can give a shoplifter a feeling of being watched. Some may think they are two-way mirrors. It can also make the store look like there are more people browsing than actually there.
Consider mirrors when decorating your store. They can add an ambiance that you may not have considered originally.