I have never heard of this intrinsic
value before until I come across this page on MDN.
From what I know intrinsic means
It allows you to set the width of an element to stretch wide enough to accommodate its children. So, if a div element contained a wide image and some text, the div would stretch wide enough to accommodate the image, and the text would begin breaking at that threshold.
Definitely experimental and not widely supported: http://caniuse.com/intrinsic-width