yes but why the picture of sakura? Why not just use one of itachi and sasuke?
It is certainly confusing as I can't predict other person's thought pattern 100%, but it could be an attempt to show that the famous gesture was transfered into another context, outside of the brotherly diad of Itachi and Sasuke. To show that another person has been included, that the gesture lived on. Otherwise it would look too much like a flashback.There are no pictures of Sasuke poking Naruto, so Sakura and Itachi can be the closest approximation.
To show that the gesture lives on - this is also one of the reasons I think it is Naruto. The gesture was a recurring thing, it was the symbol of a bond. I don't see such gesture as more than a one time thing with Sakura. And I do believe that the gesture was the symbol of brotherhood in a way. Itachi was Sasuke's most important person and he just compared Naruto with Itachi in the previous chapter. Sasuke does think of Naruto as his brother. But Sakura might be his "family", but not really a sister (we have no reason to think that), just "family".
Edited by Alessa, 04 November 2014 - 08:11 PM.

(The fault, dear Brutus, is not in our stars, but in ourselves, that we are underlings.)