It's deliberate. I guarantee that it's about building a "brand mindset." They've been playing with text copy for decades.
If you say "iPhone," instead of "The iPhone," you've turned "iPhone" into a pronoun. That has a different "connection" to people that hear it.
Branding seems to be something that a lot of tecchies (including Yours Truly) have difficulty with. There's a lot of subtle psychological games that aren't easy to quantify.