Feldon 
Due to the dim lighting, it was impossible to get any good still images of the guild hall. The video walkthroughs are better anyway.
Level 50 Guild Hall (T2) video on Youtube
Level 70 Guild Hall (T3) video on Youtube
NOTE The T2 Guild Hall video above does not depict the Atrium and larger rooms being added in response to feedback about the guild halls received post-Fanfaire.