Here is what I find peculiar. If the NFL is only worried about it's image and would like to take this 'show-boating' away, they are going about this all wrong by passing new rules and punishments (penalities).
The simple solution, approach those who have the television rights and tell them, "You are not allowed to show touchdown celebrations on your broadcast." This would follow the same methodology for broadcasters not showing streakers and individuals who run on to the field.
Think about it, instead of trying to force them to do something they don't want to to do, just take away what they want; the spotlight. All of sudden when T.O. scores, we see no touchdown celebration but we do see the flag and the enforcement of the 15-yard penalty.
I would actually find this more comical and entertaining after the game:
Reporter - "T.O., congratulations on a great game."
T.O. - "Thanks."
Reporter - "What happen in the endzone after you scored?"
T.O. - "I busted out my new celebration dance, did you see it?"
Reporter - "Um, no. Could you explain it to us?"
T.O. - "Um well I did this, then I did this and then I did this. It was really cool!"
Reporter - "We'll take your word for it T.O. But we did see the 15-yard penalty and that must have hurt your team."