Catwalk floor is a narrow, usually elevated platform used by models to demonstrate clothing and accessories during a fashion show.
Models on the catwalk often use a walk which is like that of a cat, placing one foot directly in front of the other to produce an alluring swagger in which the hips take on a more exaggerated movement.
The line on a woman's shirt that connects her breasts. The fabric is stretched tight over her curves (or just her erect nipples) but is looser in between- hence the line. So-called because of the similarity in appearance to a narrow walkway between two towers.
Man, she's got some sweet tits! And look at that catwalk! It must be cold in here!