There is still some way to go with this nest. However, Sooty seems to be pretty active at the moment. You can see some moss stuck in the entrance hole, so she must have just brought another load into the box.
Yet more nesting material. As usual, at this stage the nest is being built mostly of moss. Later she will bring in fluffy stuff like feathers, or wool that she has managed to find. However, there is a little way to go before that stage at the moment as can be seen by the large area of bare wood visible at the bottom of the box.
Having said all that, Sooty brings in something different - though what it is I am not quite sure.
It didn't leave much that is visible though!
This picture was taken at about 7:30pm when all good birds are thinking of retiring for the night.