I've never been a big fan of graphical content in Tables of Contents. To me, it's just a distraction. I'm able to quickly look at a the bold-word titles in a TOC and find what I want.
But it's fine if a journal wants to put them in. It's just that they must be up to the same standards as the rest of the text. Why lower them, such as in this case:
Are the happy/sad faces really that communicative? If the general public saw this (and with the ever growing trend in open access, the general public will be seeing a lot more of this), what would they think? That scientists are taking tax dollars for research and publishing cartoons? How long before a national politician makes political hay with something like this? This really has to stop. It's not making science more understandable to the public - it's making a joke of it. If these "funny" graphical pictures are such a good idea, why aren't there more of them in the rest of the article? No, this has to stop.