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.
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.
“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.
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.