these are to support lithophanes that are printed vertically, they can be resized easily in bambu studio to whatever size you need just untick the aspect ratio box,

place next to your lithophanes so they combine with you lithophane about 0.5mm, can be sliced separately from your litho but you will get a error that parts are touching (it will still print ok) or select the 2 supports and your litho and assemble, this will print faster than just touching, resize to hold multiple lithophanes of the same size to print at the same time, add brims if you want a bit more bed adhesion, easily broke off from your print