This is one half of a stereo pair, much enlarged. The dating is most uncertain. The bridge is stepped rather than sloped, so we are looking at the original bridge of 1749 before it was rebuilt in 1867. The bridge looks in rather poor condition. The right-hand side of the bridge seems to be leaning inwards. There are iron hoops connecting both sides of the bridge together - it is unclear whether this is to support a canopy, or whether the hoops are there to prevent further inward leaning of the sides.
Two adults are shown, who appear to be the same as those who appear in many photographs of the 1850s. The nearest one, with a top hat, is probably the (Head) Porter. He lived in one of the cottages behind the camera position. A small girl is standing beside him, and a small boy is sitting near to her. Might they be the Porter's children?
On the far right, a sloping pole is part of a tripod supporting a sapling horse-chestnut.