SPOILERS for Series 6 Episode 4 of Doctor Who. Keeping this one out of the featured gallery at least until the episode comes out on DVD.
Okay, I ADORED this episode. I'm one of those fans who came to the show late (in the last two years), has watched all the new series and half of the old series (it helps me think... what? I do have a life). Personally, the old series has my heart. I adore the new series, but my favorite anything always is in the old series... except my favorite episode. This is definitely it. I have always loved the quasi-alive-but-we-really-don't-know/understand aspect that the TARDIS has always had. I think that this episode stayed true to what the TARDIS has always been in all the Doctors (okay, still haven't seen much of the 2nd or the 7th, but in all the rest) while becoming something more. She's a being, but of an entirely different sort from us. The events of this episode allowed us, and most importantly The Doctor, to be able to understand her somewhat.
Okay, now that I am done gushing (mostly). The aim of this wallpaper was to show the friendship between the two. All of the Doctors are shown with the TARDIS/in the TARDIS. The 11th is 'leading' her as usual. He thinks he's the one leading and it looks like it, but it is really her. This time, however, she's in a form which can be communicated with and we are able to see her emotions on the matter. All the other ones are more of a captain and his ship since that is more or less the way it was before.
Made with GIMP in 2011. All rights regarding Doctor Who belong to the BBC. All hail Neil Gaiman for this episode!