I already offered the view that mindfulness is that mental function that keeps awareness 'bare'.
Awareness or consciousness is something naturally 'bare' or pure unless it is obscured by defilement.
(I trust you have read the Buddha's teaching on luminous mind in the Anguttara Ones.)
The skill of mindfulness is bringing to bear the object of meditation.
Instead of awareness bearing in mind naked dancing women, it has the skill to bear in mind the meditation object.
Thus the Buddha advised right mindfulness is awareness or contemplation of the four satipatthana rather than the four Spice Girls.