A set of photos has leaked on January 6 2016 showing someone handling what is alleged to be a dummy unit of the iPhone 6c (or iPhone 7c OR iPhone 5e, depending on which rumour you believe). The leaked images show a 4in device which cleary draws design influence from the current iPhone 6s and, it would also appear that rumours of a Touch ID Home button on the smaller model are indeed true - at least assuming the dummy is legit, of course.
The images emerged via Nowehereelse.fr, a site known for publishing accurate information. It also appears that the phone is a bit on the chunky side and we can make out what looks like a 3.5mm headphone jack, so even if the rumours of a super-thin iPhone 7 with no 3.5mm port are true, it would seem such things don't apply to the iPhone 6c/iPhone 7c/iPhone 5e as well. There's not much more info we can draw from the images though, but here they are for you to have a gander.