In my novel I'm working on, I have a spell placed over the servants of the MC's castle, so that the MC's prisoner, Celine, cannot see them, but rather what they are doing. For instance, I have several scenes where she must adjust to not seeing them coming, but gets freaked out when they brush her hair, serve her food, ect., cuz she can see the brush floating up and down and such. I'm unsure of how to describe the contents of the spell, exactly. For instance, why would Celine be able to see them ladelling her porridge into her plate during breakfast, but she cannot see their clothing? I'm wondering how the spell could have been worded, so that the things the servants touch are visible, but their clothing is not. Any ideas?