Mischievous Macro Smirk

Giants! They're big, they're strong, and in the right mindset can crush you like a grape without any second thought. Good, evil or Neutral, tinies are bound to suffer.
Many giants who are not homicidal maniacs are often nice and gentle, or at least not evil enough to be tormenting or harassing those smaller than him/her. Then that giant has a realization, they shouldn't have to listen to that annoying bully, that "official" who's been trying to ruin his life, that scam artist who tries to kill him, or even the not-so-"Big Bad". They tower over those "puny insects", why should they bother with listening to them or let them control him/her?
And it happens: The giant smirks, cocks their eyebrows and sometimes even points out that they can do whatever the hell they want, usually followed by the giant obliterating and chance the target has of gaining the upper hand.
This reaction is what's known as the Mischievous Macro Smirk, a common reactions for giants to make when they just realized they're in control, though expect to see this face whenever the giant has a "neat idea" on what to do with the tinies in question.
Despite the evil name, this is most common with heroic giants, mischievous ones, or previous victims of abuse, though god forbid a giant makes this face at you, as this usually precedes the giant doing all sorts of painful/humiliating things towards you. 
Not to be confused with the "Evil Giant's Grin", which is the "evil", villainous variant of this trope.