Whispering Willows

In chapter IV, as you proceed there are three knights that you have to move their arms to the correct position to open some doors. There are two on the lower level and one on the upper level. The door next to the corresponding Knight will unlock if you set the position correctly. You're supposed to use the paintings in the background as a hint.
I can't get these to come in directly so I dropped them in imgur - here are the three knights in the correct positions. https://imgur.com/a/i1ovDOR
The 1st, lower Knight has a rapier. The hilt needs to be on the left, and the tip pointing to the right, slightly above the center line.
The 2nd, lower Knight is through a door and is holding a halberd [Stick with an axe on it]. The axe portion needs to be pointing up, and the stick portion pointing down. Once his door unlocks, you can get a mace.
The 3rd Knight is on the level above, and needs the mace. Once you give him the mace, rotate it so the heavy portion is pointed to the left, and shorter pointed to the right. It's around a 45* angle.
The achievement will unlock after you set the 3rd Knight's arm correctly.