All sorts of creatures call The Cage(or Sigil as the Primes call it) home. Here, balrogs rub shoulders with hound archons, and slaadi might play a game of dice with modrons, all under the ever-watchful eye of the Lady of Pain. This being however, she is different.  Some sort of half-breed maybe? She doesn't quite match any of the planar creatures you know of - but it seems you've caught her eye.  She seems friendly enough, maybe a conversation over some tea might clear things up... then again, everyone has their own secrets here in the City of Doors.

A portrait of Jasmine, my half-dragon rakshasa rogue-at-large, passing down the streets of her adopted home, Sigil. It's one of a very few places that she knows her former family can't track her - with the variety of beings in the city at the center of everything, even her unique looks don't stand out, and who would expect a proud (former) rakshasa noble to take on a streetname like Tigerlily and slum among thieves and ne'er-do-wells?  Not to mention how easy it is for a shapeshifter to lose herself in a crowd. And if some agent seeking her head does manage to find her whereabouts? Every opening in Sigil is a potential portal - if you know the key. And there are many prime material planes out there...

Stepping outside in-character motivations, I've always thought Sigil was a perfect match for her for a few other reasons. Not only does it allow her to show up in any setting I might wish to use her in; it also provides a logical place where a half-demon/half-dragon can fit in without any issues. The urban environment is also a great playground for a rogue or rogue-type, and given how every version of her background story involves jumping blindly through a planar portal... well, you could say that all roads lead to Sigil. 

As for the depiction itself?  This one is from Aurru and I think it came out wonderfully! It's a perfect fit too for the kinds of portraits you might see in the Baldur's Gate or Neverwinter Nights game series... it's just too bad that Planescape: Torment's plot is tied so tightly to the Nameless One that I can't use her as my PC instead.