This is a new name given to what is really a long established way of applying face masks, especially if you’re used to seeing a facialist.
Simply put, you apply different types of masks to match the concerns of different parts of your face. Very few people have ‘normal’ skin all over their face, so this is just a way of tailoring your skincare to get better results.
For example, you may have an oily T-Zone, so you would apply a deep cleansing clay face mask to that area; you may also have dry patches on your cheeks so you would apply a hydrating skin plumping mask; suffer from hyperpigmentation and sun damage on your chin and forehead so you apply a brightening exfoliating mask, so on and so forth.
Clearly, it’s also an exercise in spending, so if it’s not for you due to cost reasons invest in a mask that addresses the majority of your skins overall condition. A lot of brands now have mask wardrobes (another funky name for sets, lol!), so will encourage you to buy the entire collection. You can, but you could also have some fun shopping around and putting together your own mask wardrobe