Compare:
Tom Brevoort, recounting a rule Stan Lee had at Marvel:
Reed doesn’t stretch his neck. This one’s been largely abandoned over the last ten years, but it was a guiding principle for Mister Fantastic for decades. As a more serious, intellectually-minded individual than other stretchy heroes such as Plastic Man or the Elongated Man, it was felt that having Reed stretch his neck (or his eyeballs, or his ears, etc.) would look too undignified.