You can find all kinds of sites with pictures of the Jana Bahaa, and snippets of information on its history and significance written by pros and amateurs alike. These are all much better what yours truly could offer.
It is quite impossible to do justice to the magical atmosphere of this small Kathmandu courtyard with photographs. Try to enter the courtyard from the West rather than the main entry through a dark alleyway - you'll have to trespass a house for a short while but it's worth it - thus ending up at the back of the shrine. In this way the splendour of the shrine (and the pigeons in front of it) won't hit you right away. Make sure to tap one of the beams on the way and take its blessings on your head. I have no idea what this means but I have seen locals do it. Your trespassing has better chances to be forgiven.
The eastern facade.
Spectacular gilt-copper images.
More of the same.
[pictures taken by the author, September 2007]