There is a diffuse and generalized process occurring in the lungs of this neonate. The opacification is centered in the airspace although there are interstitial opacities too. There is no significant effusion. 

Given the history of recent cesarean section, one might be led towards TTN as the diagnosis.

However, there are features that suggest this neonate is preterm (lack of humeral head ossification and a bell-shaped thorax).  Since the neonate is ventilated the rule about only seeing RDS in low-volume lungs does not hold.

On day 2, there has been some improvement, but not the marked improvement one would expect if this were TTN being treated with diuretics. The diagnosis here is RDS.