it's interesting what you said.. but I don't think it will be comedic... this time I think it will really be something serious... My theory is that Sanji is some noble or some prince... and when he saw his wanted poster he went to deal with his parents or government or something like that xDD stupid I know :D ... but I really hope that it's not something too serious..
Hope that we will see in next chapter what did he write in a note...
Maybe Sanji saw his picture on the new wanted poster, got tired of always getting a "bad" pic of himeself, and left to go deal with it. I totally see him scaring the photographer sh*tless. His figure looming menacingly like those before a major battle, smoking a cigarette, and trying to be suave and threatening. The photographer is shaking, saying he can't do it because he doesn't have the authority, plus new pics only on new bounties. Then I totally see Sanji's overly dramatic recap of how the previous pic affected his life, crying like he does when he recounts of his time on new okama. Marines burst in without Sanji resolving his "crisis" and it ends with him evading them and returning to the ship.