I found this image of 2 piers of a Grider bridge with varying height. By any change could this be part of the design? The bridge is supposed to be a flyover for traffic decongestion.
It could be the tops are at just the same level, only with deeper beams to cover larger spans at the right hand side, except the last beam upfront is not installed yet.
The missing beam and the angle of perspective creates the illusion that the top is stepping down to the left.