For all of you wondering about compression That is not compression, it is perspective!
+1 - it's due to the fact that the camera-to-subject distance was changed to maintain framing, and has nothing to do with the focal length of the lens.
PBD has posted visual examples of this before, as have I. I prefer mine, mainly because I was able to imbibe the subjects after the test.
I remember that thread well. Personally I thought PBD's example was amusing because the lady in the comparison had either been posing for far too long or had been asked to do this type of thing far too many times before. It was of course also informative as was yours, where it showed a good example of wiki getting it wrong, or at least being misleading, a warning to those who use wiki as a ready reference for posing as an experienced expert on the web.
The 'compression' seen in perspective can be confusing photographically. PBD says compression is an illusion, but it's worth remembering that the 'illusion' is what we see.
Anyone with a zoom can do a quick test for themselves. Using a zoom that goes from wide angle to telephoto - say the 24-105, take a shot of a scene with objects of some sort at different distances away from you at 24mm. Then from exactly the same position take the same shot at 105mm. Download both images, then crop centre of the 24 mil shot to exactly the same as 105 and enlarge it to the same. It will be identical to the original 105 mil shot in perspective despite the fact that on the 24mm shot the perspective seems to be pulling apart - an illusion.
Incidentally the 24-105 is so well corrected the two images are
nearly identical in that you can virtually overlay them.
Back on track with the 135L, the head shots show that once you are over a certain distance from the model there is little flattering change to the perspective of the face, and that flattering distance starts with the 135mm.