Please post the URL for your blog when you post to this forum. Or link your username to your blog. The latter is very easy to do. Dashboard > Users > Your Profile. Scroll down to where it says ‘Website‘ and fill in the address of your blog ( ie the complete URL starting with http:// ) and then click ‘Update Profile‘.
All wordpress.com themes that are made available to us must be first adapted so they can run on this wpMU (wordpress multiuser) blogging platform. The themes you see here > Appearance > Themes have been adapted from the original wordpress.org themes and when they are adapted they do not contain all the features that the original wordpress.org themes have.