Yes, these two people are the same person, my cousin, the actor Nick Tennant. To my mind, that is what great acting is all about, the ability to assume an identity to the point where the audience sees the character and not the person playing the character. Nick has that ability.
Take just a simple example from popular culture: Magneto in the X-Men movies. The character is played by Ian McKellen, but when you are watching the movie you don't sit their thinking "that's Ian McKellen." You're thinking "that's Magneto." And you're not thinking "that's Gandalf" or "that's Richard III" or maybe "that creepy Nazi neighbor in Apt Pupil." The character assumed by the actor is what you see, and IMHO what you should see, not the actor "being someone else."
Another good example would be Hannibal Lecter, engraved on the movie-goers mind by Anthony Hopkins (BTW, young Nick--above--attended the same drama school as Mr. Hopkins). That performance, powerful as it was, does not prevent you believing that Anthony Hopkins is the gritty but harmless New Zealand eccentric Burt Monroe in the must-see sleeper: The World's Fastest Indian (safe Christmas present for anyone interested in motorcycles or engineering feats of any kind).
For the record, the photo on the left is one of Nick's standard "head shots." The picture on the right is Nick duirng his time as Grumio in the Royal Shakespeare Company's 2003 production of the bard's "Taming of the Shrew" and Fletcher's "The Tamer Tamed." It was Nick's idea to play the groom's role in a realistic stage of grubbiness. Hence the look you see.