New answers tagged the-big-bang-theory
The plot and dialog from the episode answer this. Wil Wheaton is a troll, and enjoys messing with people (remember the bowling games?). And he's most known for playing Wesley on Star Trek TNG. The Trekkie vs Jedi (Star Trek vs Star Wars fans) feud is as famous as the Hatfields and McCoys (No, not that McCoy.) From wikia: At the movies, the audience ...
Wil Wheaton played Wesley Crusher on Star Trek: The Next Generation. It's a simple joke that despite seeing Star Wars, he's wearing his Star Trek uniform instead.
It originated in the move Freaks (1932), but was actually popularized by The Ramones in the song 'Pinhead'.
It appears to be this poster from Science of Cocktails (or at least pretty similar to it).: I used Googles reverse image search to find this, using this image as the reference, in case you want to find more similar images (there's a few variations of this one):
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