1. Humans have souls.
All animals are ensouled
2. We're made in the Image of God.
This is simply just another way of asking the question; in what way are we made unique in the image of God?
3. We can philosophize.
Small children and the mentally disabled cannot, does that mean that they are not persons?
4. Animals would never create/watch a show called 'Glee'.
Actually, chimps have been observed to watch television and have their favorite TV shows.
Learning sign language and constructing vast civilizations across the entire globe belie quite the gap of intelligence.
Ever consider the idea that maybe great apes are the intelligent ones and we are actually the stupid ones? They do not bother to go through all of this trouble to construct vast empires and civilizations which only lead to warfare, political corruption and all of the evils which make human human. They live together in a close unit, make the best of what they have, eat what nature provides, have hot monkey sex all day and sleep. From the sound of it, I would say that we should follow the examples set forth by the great apes; maybe then we would be in better shape. For all our alleged 'intelligence' we've sure been the most destructive species on the planet. Maybe apes are more intelligent because they have chose not to unleash the same destruction that we have upon the world.
That being said, humans fully participate in the rational aspects of existence, and don't do so merely as an accident of some other behavior. We are capable of sub-creation, art, in other words, and we are capable of revealing a depth of our character to others through language that as of yet no other animal has been able to replicate - at least to us.
Not all of us. The mute are incapable of language and speech, those who do not have hands are incapable of creating art, the mentally disabled are incapable of philosophy and rationality. All human infants at a particular time are incapable of doing any of this. So clearly our personhood must lie in something else. Likewise, what makes art and language so important or uniquely intelligent? The great apes do not have language or art and they have gotten along just fine, using their intelligence for more basic needs. Likewise, given enough training, a chimpanzee can virtually do anything that a human is capable of. They've learned sign language, how to drive a car, using the television, cooking, using silverware, the toilet, changing clothes etc. I'd be surprised if there was anything that a chimp cannot
learn to do. They've even been able to perform basic math equations and play chess.
Through our abilities and choices we can work with the natural world other than us to create a glorification of God in all things, thus bettering the world itself, but as has been proven by history, we are not capable of such unity as of yet. Sometime though, and sometime soon.
But this does not answer the question but only rephrases the question once again; why did God choose us to glorify Him and what is the special aspect about us that gives us the potential to glorify God in a way that no other creature in the world or universe can?