When the cars were replaced, the original seven-window design also replaced with five windows. The latest cars were designed to have five windows - one of the reasons for that is they give better views out.
Ramps added to secure the doors at each end of the cars during travel and to assist people with wheelchairs and pushchairs to negotiate the gap between the car and the landing at a station. You can see one of the stainless steel ramps on this car secured with the cross bar on the right.
The ramps at the bottom are steeper because the cars arrive slightly higher against the bottom station. The reason for this is that in an earlier refurbishment the track was relayed and left about 9" higher at the bottom than it was originally! Compare the doorways at the top and bottom when you ride.