What's more frustrating than being ignored?

Any tips on how to get a toddler to listen?

My biggest problem with Tiegan's behavior as of late is that she doesn't listen to/pay attention to/remember what I tell her. I work so hard to explain things in a way that she'll understand, but she can't just be serious for 2 seconds. I realize that settling down and listening through a short "lecture" is difficult for someone so little. I don't expect her to completely resist temptation to look around a little or drift off a bit if I'm talking too much.

I'm NO expert on the subject, but I think she should be able to at least repeat a sentence 2 seconds after I say it.

TV is a big factor. It pains me to say so, because I always swore I would never let the TV raise my child(ren). When we drove to Briarwood mall today, she knew exactly what Macy's was by the big red star, because she had seen the commercial on TV. This happens a lot. She repeats practically everything she sees/hears on TV. She has an extremely sharp memory for details, even with things outside of the tube. Sometimes I think she even has a photographic memory. (But that's probably just pride or biased motherhood sneaking in).

But when I get down on her level and try to explain why I scolded her, or how something works, or why we do what we do... in one ear and out the other. She makes faces and silly noises while I'm talking. I have to repeat myself: "Please look at me. LOOK AT ME. Quiet. Look at me. Listen. Be quiet." I explain that making faces and noises at someone who's talking to you is rude. I explain what rude means.
Me: "Do you understand?"
Tiegan: "Yes."
Me: "Were you listening?"
Tiegan: "Yes."
Me: "What did I say?"
Tiegan: "I don't know."