Pictures rarely show all that you see. You will find duck egg development charts online. But before you look, what breed/species is the egg from. A chart showing mallard egg development would look different than one for muscovys as muscovy eggs have a longer incubation period. In short, be specific when requesting a development chart. Size of duck may be important too. My Call ducks hatch two days earlier than the larger breeds that hatch in 28 days.
Confused? Post what breed and we/I can help.