Are there any halachas to note for Mezuzah covers? Would it be alright to have three decorative Shin at the bottom of the cover rather than the top like you see most of the time in Mezuzah covers?
The reason there is a shin at that part of the mezuza case is because Hashem’s name is written in the parchment at about that height of the mezuza. Being that most mezuza cases are opaque, and we can’t see the writing, so we make a shin on the outside. Additionally, we don’t want to write Hashem’s name on the outside of the mezuza cover because then we will have to be careful not to do inappropriate things in front of the mezuza. Therefore, the best place is to put it towards the top.
Chovas Hador 8 ftnt. 13.