Some of those examples were clearly not real but some - the snickers bar being split - seemed pretty real.

I wonder if those very realistic shots are usable in UK adverts without disclaimers? As an example, see ads for mascara which get regulated if they use computer enhanced lashes and no disclaimer.

You might be surprised how fake the real thing can look:

https://www.youtube.com/watch?v=Ow-dDfarZuY

I'd say without a doubt that shots like 0:25 or 3:00 were CGI...

Actually, I was once talking to a friend that does photography for print ads: I was surprised to find out that most of the highly detailed stills of, say, lipstick or champagne coming out of a bottle are actual photographs.

Why were you surprised by that/How did you assume they were made otherwise?

I assumed many things were renders or that stuff was combined later in photoshop.

I thought that champagne overflowing from a bottle was not made with real champagne over and over again until you got the perfect shot.

I was also surprised to find out that when the background had a nice motion blur it was sometimes actual motion blur made with a rotating rig that had the camera and the object to be shot on it.