This is a smiling scientist of the allegedly "skeptical kind" according to this New York Times Science article.
Smiling is associated with being happy and sometimes with being blissfully ignorant of what is coming your way.
Tilting one's head is associated with polite dissent. With deceptive appearance of agreeing while not agreeing.
Are you smiling?
Is your head tilted?
Or do you still step back to the hard science?