but i think it's weird just how much insight itachi actually has to naruto's personality in how specific he was. itachi probably could've said, "the noisiest kid in the bunch" and still would've been right superficially, since that's what any dumbass could pick up when he/she encounters naruto for the first time.

but itachi points out that this kid will be passionate and will be quick to react to the scene. he seems to kno all about naruto's friendship with gaara and knows exactly what pushes his buttons.

personally, while the dialogue was amusing, i think it gave some insight into what good observational skills itachi has and how he can use that to anticipate his opponent.