In fairness, that specific marketing line is more than a little silly: it can't be both smaller than an iPad and as big at the same time; both devices can't be the "perfect" size when they are different.
Like all tech companies, Apple needs to be able to do subtle iterations and improvements, and their marketing teams are left to try to add an "r" to every evolution.
It's certainly a marketing line with plenty of exageration, but I don't think it's particularly unusual.
"At 7.9 inches, itβs perfectly sized to deliver an experience every bit as big as iPad"
It's "perfectly sized" for the role it's filling (one hand, more mobile, like a pulp novel, whatever), and iPad is "perfectly sized" for it's own role (around the house, larger games, magazine reading, whatever). They can both be "perfectly sized" in a marketing world, and I'm sure the design team fussed over the exact dimensions for a LONG time.
It's "an experience" "as big as the iPad" to emphasize that it will run all the existing apps, vs their comparisons to a "scaled up phone experience". The marketing here emphasizes that the compact experience is 'just as good'. I do wonder how well UI elements will scale down, but in a marketing world it makes a certain kind of sense to me.
Yes, these claims are a bit silly, especially in a literal sense, but recall that the original iPad was "magical". It's pretty typical marketing phrasing, especially for Apple.
That said, I frequently find the phrasing funny too.
Like all tech companies, Apple needs to be able to do subtle iterations and improvements, and their marketing teams are left to try to add an "r" to every evolution.