Most Helpful Girls
I think it has to do with what types of modeling/ gig is booked. Some brands want their products to be seen as a sensual in a forbidden apple-elite type of way that can be appealing to people who want to fit into that exclusive category. Many of these high fashion brands fall will call on the editorial, runway type of model. Now, on the other hand, lifestyle/commercial models are often encouraged to smile to show happiness, relatability and inclusivity. Also, one thing to consider is that most models are booked for their looks, specifically angled cheekbones and peak features; when a model smiles, those features are lost in that facial expression.