Remember, the surgeon isn’t putting breast on your body. The surgeon is putting implants on your body – to augment your breast.
Where your breasts are on your body (your breast footprint) does not change. The surgeon cannot move your breasts closer together or further apart, nor can they move your breast up or down your chest.
How high your implant sits on your chest is related to how wide (and tall) the implant is, versus how long your chest is. If you have a long chest, your implants will never sit high. If you have a short chest, your implants will always be high. Bigger implants make the upper pole/chest more obvious, but the position does not change.
The gap between your breasts is determined by your natural breast. A surgeon cannot widen this distance. It can be made more or less obvious, but the actual distance between your breasts does not change.