[DeweyCA]

The ropes look awfully short. It doesn’t appear that the people would drop much. Instead of a quick snap of the neck, it looks more like a slow strangulation would ensue. Maybe a slow death would be more appropriate in some cases.

[TaMoDee]

While it cannot be seen in the photo a “real” gallows sometimes had the extra footage required for a longer drop coiled on top of the beam. Hence the quick snap of the neck.

[jonno]

“The ropes look awfully short”

I’m not sure, but I think some length of the rope is laid over the top of the main beam.

[TigersEye]

The rope doesn't move much it's the body falling through the trap door that travels. They hanged quite a few men at Ft. Smith (86) so I imagine they knew how to do it right.

The gallows in the picture is a reconstruction of the 1886 gallows and it may not have the trap door as described since it wasn't built to be used.