We now create an accurate edge to the subject.
Before you do, think about what parts of the outline will be undercut and what parts simply end up at the background. When you undercut, the background continues visibly beneath the subject; so stabbing into the background here looks bad. Hold back on the parts destined to be undercut - stop short of the background - until later. We tackle the undercutting almost last thing.
I'm using a double-bevel, carving chisel for the straight edges of the frame around the dragonfly 'frame'. If you don't have one, you can use an ordinary, single-bevel, carpentry chisel.
Apologies for the film being out of focus 2:50 - 6:19. Can't explain what happened there. You can still see what's going on but it's a little fuzzy. Sorry.
Related videos: Put 'setting in' into the search box, top left, and you'll find lots more examples and explanations of this common carving practice.