Kind of odd. On modern walls, covered with sheetrock, it's good practice to "line" the walls, straightening out studs so the sheetrock lies flat. That's not critical with lath-and-plaster walls, because the flatness is achieved by how well you do the plaster work (on our house, the outside of the perimeter walls are held flat, so the siding lays flat; inside studs are all over the place, but you'd never know, thanks to the lath-and-plaster).
Not sure what the heck this thing is.