MILEY AND BINDIS

About bindis: Bindis are worn throughout South Asia, specifically India, Bangladesh, Nepal, Sri Lanka and Pakistan, by women and girls, and no longer signify age, marital status, religious background or ethnic affiliation. The bindi has become a decorative item and is no longer restricted in colour or shape. Self-adhesive bindis (also known as sticker bindis) are available, usually made of felt or thin metal and adhesive on the other side. These are simple to apply, disposable substitutes for older tilak bindis. Sticker bindis come in many colors, designs, materials, and sizes. Some are decorated with sequins, glass beads, or rhinestones.
So why is Miley wearing it? 1.: Because of its "power": The area between the eyebrows, the sixth chakra known as the 'agna' meaning 'command', is the seat of concealed wisdom. It is the centre point wherein all experience is gathered in total concentration. According to the tantric cult, when during meditation the latent energy ('kundalini') rises from the base of the spine towards the head, this 'agna' is the probable outlet for this potent energy. The red 'kumkum' between the eyebrows is said to retain ENERGY in the human body and control the various levels of CONCENTRATION. It is also the central point of the base of the CREATION itself — symbolizing auspiciousness and GOOD FORTUNE. 
2.: For decorative purposes: With changing fashion, women try out many shapes and designs. It is, at times a straight vertical line or an oval, a triangle or miniature artistry ('alpana') made with a fine-tipped stick, dusted with gold and silver powder, studded with beads and crusted with glittering stones. The advent of the sticker-bindi made of felt with glue on one side, has not only added colors, shapes and sizes to the bindi but is an ingenious easy-to-use alternative to the powder. Today, bindi is more of a fashion statement than anything else, and the number of young performers sporting bindis is overwhelming even in the West. 
Source: Teen Stars World