The first is emotional. A middle aged woman holding a hot apple pie can seem extremely beautiful because it evokes memories of doting mother. A wedding picture can seem beautiful even if the people are wearing gowns outlawed by the fashion police. Simple photos can lack the hallmarks of "sexy" and "glamour", but still strike a strong cord in our hearts.
The second is the extreme. Familiar images are transposed or put out of normal reference. The result is a haunting element that impresses us as beautiful. The elements, by themselves, would be mundane or not classically beautiful. The aggregation is more than the sum of its parts. A really good photographer can imagine the extreme and produce it for their audience.
I strive of some of both. Neither is terribly easy and I relish finding these kinds of beauty.