That is called a bindi. A bindi is a forehead decoration worn in South Asia (particularly India, Pakistan, Bangladesh, Nepal, Sri Lanka and Mauritius) and SE Asia. Traditionally it is a dot of red color applied in the center of the forehead close to the eyebrows, but it can also consist of a piece of jewelry worn in the same area.
Traditionally, the area between the eyebrows (where the bindi is placed) is said to be the sixth chakra, anja, the seat of "concealed wisdom". According to followers of Hinduism, this chakra is the exit point for kundalini (coiled or corporeal body) energy. The bindi is said to retain energy and strengthen concentration. It is also said to protect against demons or bad luck. The bindi also represents the third eye.
In modern times, bindis are worn by women of many religious persuasions in South Asia and SE Asia, and is not restricted to Hindus. Many Muslim women in Bangladesh and Pakistan wear the bindi as part of makeup. It is also used in festivals such as Holi.
Depends on what color it is.. Kind of like our traffic signals.. It lets you know the mood of the wearer. If its glowing red and blinking... Run like heck and get away fast ... She could blow any minute. Hope this helps