Id call this a bug, because its output differently depending on where you view it. Im not sure if this is intentional though.

Take the following blog: http://confluence.atlassian.com/display/TEST/2004/03/09/Sample+Blog - it looks how I intended to and how I want it to be seen.

Now take the following link:
http://confluence.atlassian.com/display/TEST/2004/03/09/ - that doesnt! The text has gone grey and the heading style have changed.

Personally, I think that if you edit a page to look a certain way - it should look like that, no matter where you see it from.