I tried to grab some frames of the process. Notice how the colored water moves from the plate into the glass container. Once the candle flame goes out, you will see an inrush of water.

If you search for this on the web, you will see multiple ideas on how it works.

I took the explanation of Oliver Knill from the Harvard Math Department. He states in general terms: "The candle heats the air and expands it. This cancels the depletion of the oxygen temporarily and the water level stays down. When the oxygen is depleted, the candle goes out and the air cools. The volume of the air decreases and the water rises. The temporary temperature change delays the rise of the water"

For debate on the subject, see the following link:

math.harvard.edu