Steerpike! Steerpike is correct. For it to be a simile, you would have to compare one thing being like or similar to another thing. The sentence you have has one thing hinting at a conclusion. Not a simile.
@Steerpike! Hi. We missed you. Not a simile, @Artist369, Steerpike is correct. If you said, "... like a cat that knew some great secret," it would be.
Yeah, I am confused because I am seeing this website which is listing similar things as similes: And this one classifies as a metaphor.....? I thought a knew what a metaphor and simile was until I read his classifications. Is he off his rocker, or am I? Because "She smiled as though she knew some great secret" feels like both of those statements.
I think that this: The camp looked as though it had been through an epidemic: empty and dead. is similar to yours: She smiled as though she knew some great secret. because neither of them is, IMO, really a metaphor. Oh, the first one is, I suppose, just a little closer to metaphor, but I see both of them as descriptive. To push them further into metaphor, I could rewrite them: The camp looked like a carefully arranged group of toys. She smiled like a satisfied cat. I was going to give your third example: It was as though she was possessed by some evil spirit. some credit for being a metaphor, but... I still see it primarily as just descriptive. Going to the website that you linked to, my main reaction to many, perhaps most, of the analyses of similes and metaphors is, "What? No. Wrong."
Google definition: Your source claims using "as though" makes it a simile: I wasn't sure I agreed, so I went to another source: Here are their "as though" examples: Cassie talked to her son about girls as though she were giving him tax advice. He kissed her as though he were trying to win a sword fight. Toby manipulated the people in his life as though they were chess pieces. Breaking the three examples down to compare them to yours: Cassie talked/as though she were He kissed/as though he were Toby manipulated people/as though they were A smile sat crooked/as though she knew It would appear to be a simile. But it's a twisted one. She smiled/as though she knew A smile sat/as though she knew A smile sat crooked on her face/as though she knew What is confusing is 'as though she knew" describes the person rather than describing the crooked smile even though it appears to describe the smile. I think that's where the problem occurs. In this case, I defer to the experts of which I am not one. This thread is fun.
"A similie is like a metaphor" is a simile...because it contains the word "like"...it has been likened to, or is similar to, something else. Metaphors aren't as easy to define...but "I literally died" has me screaming NO!!!! YOU METAPHORICALLY DIED!!!!