These renderings only offer what one artist wants to see - it has nothing to do with "what we could expect". This person has nothing to do with Apple, much less Apple's design team, so it has nothing to do with the iPhone we will eventually see. If you enjoy seeing what others are imagining, that's fine - just make sure you're not setting any kind of expectations by it whatsoever.
I think it's fairly obvious we know this individual that designed the rendering has nothing to do with Apple, but they work off the predictions and rumors to build the rendering, so I don't think it matters what's an "Expectation" or not, it's still follow suit of what we
could possibly see. It's no different than reading rumors every day on Mac rumors, being that none of them are accurate. Rumors just build an imaginative theory What a future Apple product could look like based off analysts, part suppliers and Insiders.
And, Of course there is no accuracy behind these renderings. These typical mock up iPhones that appear throughout the year, have been similar to the real version we see in September on many bases, being the artist is not working off some radical redesign when certain iPhone parts surface with blurred photos. Some of them are based off with the overall physical design, but more so are correct with the display/UI, various visual cues.
For the record, iPhone mock up designer, Martin Hajek released numerous iPhone renderings last year for the iPhone 7, and was fairly accurate to what we actually saw debut during the September Keynote. So I disagree with you when you say it has to do with
their imaginative ideas, when they literally are building off the rumors that are surfacing from other various reported sources.
http://www.martinhajek.com/
Lastly, even you or anyone else on this forum, have no idea if this iPhone could actually be the real rendering. Yes, there's no way of knowing that, but all likeliness, if very well could be very accurate to what we actually see in September. This doesn't make it necessarily unbelievable, it just has no definitive truth behind it, because it was never confirmed by Apple, even if speculation has its tendencies to be the odds of determining the actual product.