Angel bath seats

First time mamma here just wondering if anyone knows the answer to this. So me and my partner are trying to find a bath seat for newborn - 6 months, in preparation for when Bambino is here. From what I've read the angel care ones are recommended but I've noticed there's two types. The regular one and the mini. I know there's an obvious difference in the shape but does anyone know why this is and what the difference it will make to bathing your baby?