Thanks for the examples guys.
I think I like the Gisele Dior ads because they are so dynamic and she is in motion (or looks to be). It makes it look powerful. Also even if she's not in motion, the shape of her knee bent makes your eye move at a fast pace through the image. WHich makes it seem active.
And btw, I changed my project. I couldn't think of a way to advertise a non-existent imaginary object without models in an appealing beautiful way. So instead I'm designing a maquette of an imaginary store which sells nothing but looks appealing to make you want to buy whatever it would be. And I talked to my teacher and she said I can use existing ads and images if I combine/edit/phtoshop them in a way that you can't tell what they were originally. So at least I can have marketing with models in my store.
But I still think this can be a very interesting discussion so I'm interested in more opinions project aside.