oh.. dear.. for all of those who just wanted to know what is that little fading shape on the picture on the wall behind Matilda from The Black Tea scene, here's one or two words of explanation...
as simple as it is - a cat! now that's a big surprise, isn't it?.. to put things in even easier manner - it's a cat's grin.. too easy now. let's make things bit confusing and deliberately leave all the fortcoming paths of interpretation of a scene in which our beautifully frozen in her dismay Matilda is trying to enjoy her black tea, to viewer's imagination. as one might say ...
reject only your ignorance and you may survive...