Through the center of the oil reservoir the potter has constructed a hollow column which, presumably, provides the ability to attach the lamp to a stick or peg for fixing it where the owner wanted it to shine.
This feature would prove ideal if the owner used the lamp in a tent, for example. The dirt floor of a tent provided a place to plant the stick and, hence, the light to shine anywhere it was needed.
The lamp also could be fixed on a very long stick to illumine out of reach areas whether they were elevated or even underground (if the stick was placed into the lamp from the top and secured underneath).
Finally, it may have had usage in a permanent dwelling by placing the lamp through a peg in the wall at an acute angle where the lamp’s side opposite the wick would have rested against the wall.
beliefspeak2 