In reference to the "x marks the spot" they claimed that it "showed you where to cover the antenna", trying to draw a parallel with covering the internal antenna on any other phone.
That is ridiculous. You aren't "covering the antenna" when you cover that spot. The antenna is the big strip of metal above that spot. Instead you're upsetting the profile of the antenna, which is entirely different.
The presentation was incredibly deceptive and flawed.
I don’t know whether they don’t acknowledge that. They showed a “X marks the spot” slide. That, to me, seems to be a pretty clear acknowledgement that merely touching that spot weakens the signal.
[+] http://www.anandtech.com/show/3821/iphone-4-redux-analyzing-...