If you commit a new image to the network as a figure tag, a copy of it gets put into the project folder. If you then close the project without saving, that image is still in the project folder, but the saved copy of the network doesn't have the tag referencing it.
If you commit a new image to the network as a figure tag, a copy of it gets put into the project folder. If you then close the project without saving, that image is still in the project folder, but the saved copy of the network doesn't have the tag referencing it.