Looks like someone has put in a shim. Whoever it was has been sensible and filled the whole neck pocket with that piece of wood. Quite a common job. Generally it allows you to get a much lower action. However, the action on your bass looks higher than the Tyne Bridge. I would take that to a luthier/tech and have a good setup done. That will make a good bass even better.
EDIT: Skank beet me to it.