I was curious so I checked, my Thorn Sherpa (I bought the frame used 12 years ago) is fitted with a triple, big ring is 46T. I used to have a 52T big ring but reduced it to 46T a few years before the photo was taken. The M6 nut you see between the water bottle cage and the frame is a spacer to hold my cage further away from the frame. M6 nut fits loosely on the M5 bolt so it works well as a spacer.
And in the case shown in the photo, the derailleur was made for a larger diameter frame, thus a shim is used that makes the size of the derailleur band around the frame tube a bit larger than a derailleur with the correct size band for the frame tube.
The front derailleur in the photo is a vintage Suntour high normal model. I do not know if some derailleurs have a higher frame tube band than others, that might be possible. Most front derailleurs are low normal, so this is an unusual one.