Depending on what you're reading, the phoenix can have a range of mythical powers: resurrection, regeneration, tears that can heal wounds, or a bird of fire and divinity. In my books, the phoenix represents new beginnings, and second chances.
I find it odd sometimes that while the greater effect on the world around us is our actions, the things that have the more profound effect on our inner world are our inactions. You know the stories: things you could have done, things you would have done, but just didn't. Or the things you ended-up doing because the alternative was, for the stupidest reason, too difficult.
In this picture, a world has dwelled on its own inactions for far too long. As a result it has become dull, devoid of life, and an eyesore to the surrounding space it occupies. Yet, as fate would have it, that world was given the chance to fix the regret that caused it to turn down the path of decay. That chance is in the form of a phoenix, rising from the core of regret, glowing bright colours and spreading a form of hope over that world and the worlds around it.
We're not all fortunate enough to have that, but for a bird born from its own ashes, the phoenix is a very lucky creature. To be given the chance to fix a broken memory, to be allowed to destroy one regret, that's resurrection right there. Sometimes, all we need is a second chance.