Best tool for chrome fittings plumbing at home
I must be blind, but I can not see from the picture where the chrome plating has been removed by the use of a pipe wrench or any "jaw marks" from any tool. The only thing I see is the corrosion near the wall entry and a small ridge from when the valve or part was cast.  When working on a chrome plated fitting or piping piece that is visible and must not be adulterated or marked a strap tool should be used to tighten the fitting. On some occasions, depending on the construction, an open end wrench or adjustable wrench that has flat jaws and no teeth can be used as long as you use great care not to mark or distort the piece you are turning.