If the top on that burner forms a seal, you may want to put a vent hole in it. DAMHIKT.
As the burner heats, alcohol inside evaporates and starts to build pressure. Without a vent, the pressure can force liquid alcohol up the wick tube and out onto the table where, of course, it is ignited by the flame.
Extended running at a show without a vent allowed me to ignite the paper cover on the exhibition table. Worse, since an alcohol flame is virtually invisible, it wasn't until my hand started burning that I noticed. It is not one of my fondest memories.