It’s not really a forgery unless it is used for the intended purpose. They can claim it was for entertainment purposes.
If you are refering to the original fake, it is there as a dissembler. Plausable deniability but as proof for those who want the believe in the change that obamas change can change to bring in a changing way.
I think the kos fake is just a means to create a disposable fake that can be dumped if checked to closely. The question is who made it and who distributed the fake.
Not on the Fight The Smears site which is dedicated to debunking untruths and is a part of Obama’s official web site.