Hi 

would anyone have any experience of making an optical illusion of a hummingbird into a flower ? 

probably made of foam so it is very lightweight and on a sturdy wire that feeds all the way into the flower -- just changing colors there to trick the eye into seeing a beak/stamen and inserted into the cake -- usually the wires from making the flower and the bird are all wrapped together with florist tape and often covered with chocolate to be inserted safely into the cake

Now that I’ve seen the pic I agree w/K8  the beak is wire inverted into the flower