This is a model of a dodo on display in the Museum. It was created by looking at the remains of the dodo in museums around the world. Unlike many of the drawings and paintings of the dodo, this model shows the dodo as being quite a slim bird.
Some of the old paintings of dodos were drawn from birds that had been brought back from Mauritius to Europe. They were not fed their proper diet, and got fat - this is why dodos may look quite bloated in these pictures.