Yes, makeup can increase confidence because for some people it boosts their self-esteem. If they feel self-conscious about their appearance and they can use makeup to cover up their blemishes or hide scars or other skin imperfections and that makes them feel better about themselves. Even if people are not trying to hide something but are just trying to make their eyes look bigger or their eye lashes look longer, if it makes them feel better, it will increase their self-confidence.
In fact there is a name for this psychological phenomenon and it’s called the “lipstick effect”. It is described as not only giving a confidence boost but also helping to improve a person’s attitude and personality.