Now compare that to the same pipe in every other angle, most easilly seen in the East version, because of the pipe location in it, but it can be seen from every angle.
In the W version, it's an iron pipe
in the N, E and S versions, it's a copper pipe.
Okay, this is a trivial issue, agreed, but still an inconsistency.

Top row: N, S, E: Copper
Bottom row: W: Iron