"¿Te gusta aquella guitarra?"
Translation:Do you like that guitar?
However, Google got me this: https://forum.duolingo.com/comment/79549/Difference-between-aquel-aquella-and-eso-esa
"That over there" is the way you should think about aquel, but not actually say. It's usually not that far away.
You're talking about the guitar that's back there in the corner of the store. :)
Usually, ese is used for things that are relatively close to the listener, and aquel for objects that are out of reach for both speaker and listener.