Society is pretty hard on women overall. There are so many messages to women about how their looks can bring them power and give them relevance. There is a rather deep subconscious fear in many women that if they lose their looks they lose their power and relevance too and they can have a deep fear of abandonment attached to this deep message.

When men age they tend to look more distinguished, some even get more attractive as they get older. It's not the same for women. It sounds like your wife has a deep insecurity and she flirts and dresses up to get attention to let her know she is still desirable. She is dressing this way for herself and hoping to get attention so she can feel better about herself. She may be attractive enough for you, but she doesn't feel it for herself and this is something she does to help her feel it.

This very challenge in women is SO HEAVILY MARKETED it's just incredible.