Great piece for developing you turning skills but I agree as a practical item I would be concerned about it's stability. Especially with a burning candle on top.
I see this design error with new wood turners in items like yours and also with pepper mills and vases (no fire hazard there). IMO these tall designs need the appearance of more weight at the bottom.
In person it doesn't feel tippy, probably due to the wood itself being so light (Pine, although it being light could be an issue in and of itself) but it isn't something that's left unattended either way, as it's fire lol