On the table, next to the candle is what looks like a dog shit in a jar, with a wick in it. Either that or Shrek made the candles!!
I doubt we can blame the photographer for brown candles. There are actually two of them, both lit! They did miss the moment though. The candle is already lit and they are backing the flame away.
I have to wonder how the symbolism works. Two candles used to light a third makes some sense as a two become one sort of thing. Lighting three candles from a butane barbecue lighter doesn’t do anything for me. What are the couple trying to say?