I use a larger than 8 digit pass code on my iphone. It looks different.

Using a default 4 digit code, you end up with a numeric pad and four boxes. If you use a longer than 4 digit code but stick with numbers, it gives a single box to enter the pass code in but presents a numeric pad. If you use letters at all, it switches to a qwerty-ish keyboard and a single box to enter the pass code.

I'm not sure because I'm not running iOS 9, but from screenshots on the web it looks like the length of the passcode is displayed on the lock screen.