Yes, you are correct, this is a Literary question, but we now have to use Formats Guidelines for some Literary Issues.
Since the two sources differ in how to handle this situation, it's important to keep in mind how the emoticon is being used.
If this were a picture of a happy face, ok, no problem, the EBAE reference would be fine.
However, after looking at the print example, the text is clearly using typed characters to represent the happy face, it is an emoticon not a picture. In the age of texting and emoticons, and with the new thought process to follow print, I still believe that Formats has the best example of how to handle this situation.
edited by SBorboa on 2/19/2013