Real gold leaf (24k yellow gold, in loose-leaf form) may melt, but it retains material presence and color.
"Mimic gold", an alloy or even colored other metal, discolors through oxidization and distorts based on melting temperature.
"Gold on base", as a painted-on coloring, burns away to carbonized ashes that tend to float away. "Gold on base", as transfer leaf (pure gold leaf on backing): the fragile gold leaf is most likely fractured by the burning backing and tends to drop off with pieces of the carbonized backing. The video does not clarify the type of "Gold on base", painted or transfer.