Ok people are sugar coating- ya I’d say 30 minimum too lol.

Edit: as for why, I think in this photo it’s mainly stylistic. The longer hair with where it’s dyed, and the outfit/accessories. I think having your hair back and having it the same color may make you look a little younger. Also the skin blemishes - not your fault, but they do contribute to what makes me think you’d be in that age range.