There are some funny things in this artwork. Sorry Aroma-chan, but I will comment 🤣 The nails Robin is nailing down in those clapboards, there are screw slots on them. A nail do NOT have a slot, only screws have slot for nails are to be hammered, not screwed in. And when you will hammer a nail on a wooden board, never hammer it at a 90º angle because in doing so you will face maximum resistance from the wood, running the risk of splitting it. Hammer it instead at 45º. You will find it way easier to nail it down. By the way, why is Robin driving the clapboard on the air? Scroll down the image and see that the wooden beam she's about to nail down that clapboard on is, in reality, far from where she is. There's no beam behind it. Another thing are those wood shavings on the axe's blade. To correct some imperfection on the wooden plate one should use a leveler, not an axe. And her boot sole should be half as thick. Without mention the sledgehammer she's using. That thing is too heavy for the kind of nail she's using. The nails will bend at the first hammering. She should be using a simple hammer instead, or thicker nails.