This is actually a portrait of emptiness, even though it glitters with galaxies. The bright elliptical galaxy in the top center, ESO 306-17, has absorbed every galaxy around it and grown to monstrous proportions.

Over at Bad Astronomy, Phil Plait explains:

ESO 306-17 sits about a billion light years from Earth. In this picture it looks like it's surrounded by other galaxies, but that's an illusion: all the other galaxies you see here are either much closer to us or much farther away . . . Michael West, who led the team that took these images, tells me the little elliptical at the bottom left of ESO 306-17 may be interacting with it. It's difficult to tell; but what is certain is that there are very few galaxies near the big one, far fewer than you'd expect.

Plait adds that this lonely galaxy shares certain properties with our own cannibalistic galaxy, the Milky Way. Both our galaxy and ESO 306-17 are surrounded by globular clusters left over from galaxies they consumed.

You can contemplate the universe in higher resolution with this gigantic version of the image.