This diderm cell is about halfway through cytokinesis. The two daughter cells are still connected by a wide bridge of cytoplasm, but the inner membrane and cell wall have drawn in all around.
The cytokinesis process is similar for diderm bacteria, as you can see in this Idiomarina loihiensis cell, with the cell wall and inner membrane growing inward. The process is almost complete here, with just a thin channel of cytoplasm in the very middle connecting the daughter cells. Notice the cell wall zippering apart at the edges of the septum. For another example slightly earlier in the process, check out the Learn More (⇩).
This diderm cell is about halfway through cytokinesis. The two daughter cells are still connected by a wide bridge of cytoplasm, but the inner membrane and cell wall have drawn in all around.