I have had a hectic few days, so my apology for coming into this discussion late, Suz.
(FWIW, my so called measurement is 5.25 cm).
YES!! I was the one that strongly suggested that you cut off your hair again. Truly, Suz, never grow your hair out to anything that is not short. I am with your sweet Mum 100%. You undeniably rock a pixie.
There are MANY variables as to why I think a pixie works and most of them have been covered already. I also have very strong feelings about when long hair works. Both styles are extreme, which is why they attract attention.
This very discussion confirms that style is art and *not* science. I trust my eyeballs much more than a measuring tape. We are walking works of art full of lines, curves, colours and textures that play off each other. Finding harmony between them cannot be bottled down to measurements, but to how they effect one another as a whole.