It takes a time to figure out how to mount on the nest.
The male Grebe is joining the female on the nest. He found a little free space and was able to balance on it very well.
But for how long the male Grebe is going to stay in this small space? The female obviously isn't going to move. Why should she?
The male Grebe managed to settled more comfortably but didn't stay on the nest for a long time. So much should be done for building the nest to make it longer, wider and stronger.