I've noticed this in match-sticks, and mango wood. After the flames die out, the brand glows red for a while. The glow is brightest right before it dies out.
My guess is that immediately before the glow dies out, any air channels in the wood are fully dried by the heat to the extent that the 'reverse wind' sweeps in to oxygenate the burning portion. This wind is so strong that the burn cannot advance and therefore glows brightest right where it is before burning itself out. This is just my guess. Why does it glow brightest before it dies out?