This car seat is "convertible" because it goes from using a harness sytem to restrain the smaller child to a seat which uses the car's own seat belt sytem, i.e. a booster seat, for the older child. It is not the type that can be used as a rear facing infant seat.
I have the same car seat for my granddaughter. It is the brown version. Lighting can change the look of the colors. The pad moves up as the straps are raised. It's hard to tell from the pics if it is the same seat but what is obvious to me is the fact that the last pic shows the pad in a lower position than it should have been for Caylee's size. The slots that the straps go through should be at the child's shoulder level. In pic 3, they are very low and do not even have the straps running through them as they should have. The straps remain in the slots, this isn't something that changes while using the seat. The straps should be visible in pic #3 and the slots they run through should be much higher than is shown.