Maybe. The pretty generated picture, how is it generated? It references "www.websequencediagrams.com" but when I go there I get a 500 error.

Aside from the pretty pictures it's pretty devoid of information.

I think they submit the sequence description file to that website and capture the returned image.

Author here. I used the api as provided by the site author. Details here:

http://www.websequencediagrams.com/embedding.html

Very cool. Thanks.