Great to see that the dev team are working on somehow to make the site better and feel more personal and what better way than giving the users the power to add their own touch to their pages.
I just did mine. I'm not sure what the dimensions are and it came out a little blurry but I'll try to fix it.
I'm loving the look of your own @stellabelle. Especially that 'follow, follow, follow' bit haha
Try doubling the size of the image if it looks blurry. This will ensure retina screens also render the image sharply..