Symbolism, Imagery, Allegory
At the front of the Ministry of Magic is a set of five golden figures:
Halfway down the hall was a fountain. A group of golden statues, larger than life-size, stood in the middle of a circular pool. Tallest of them all was a noble-looking wizard with his wand pointing straight up in the air. Grouped around him were a beautiful witch, a centaur, a goblin and a house-elf. The last three were all looking adoringly up at the witch and wizard. Glittering jets of water were flying from the ends of their wands, the point of the centaur's arrow, the tip of the goblin's hat and each of the house-elf's ears, so that the tinkling hiss of falling water was added to the pops and cracks of the Apparators and the clatter of footsteps as hundreds of witches and wizards, most of whom were wearing glum, early-morning looks, strode towards a set of golden gates at the far end of the hall. (7.66)
This statue at the front of the Ministry of Magic demonstrates the Ministry's official opinion on the status of the different magical creatures in the wizarding world. At the center is a "noble-looking wizard" with a beautiful witch next to him. Then, next to these magical folk are three creatures looking "adoringly up." Now, a centaur is half-human, half-horse, so how a centaur could look up at a wizard and a witch, we don't know.
This condescending view of house-elves, centaurs, and goblins – that they must all look up to magical humans – underlines Bill Weasley's suspicions in Chapter 5 that the goblins, fed up with mainstream wizard prejudice, might join Voldemort out of desperation. What's more, this statue also suggests that Professor Umbridge's prejudices about half-humans – and perhaps about all magical creatures – is more widespread in the magical community than we might like to think.
When Professor Dumbledore tears this fountain apart to protect Harry from Voldemort's Killing Curses at the end of the novel, he's using the tools that are near at hand. But there is also a symbolic value to Dumbledore's destruction of these statues: Dumbledore is willing to use whatever tools necessary – centaurs, house-elves, whatever – to fight against Voldemort. In this struggle, wizarding snobbery about other magical creatures can only get in the way of achieving their goals. Professor Dumbledore doesn't support the values that these golden statues represent, so no wonder he is so willing to destroy them.