This would be Addy's siggy or signature. You can find it in her every posts.
Want a Burberry or LV authentication? Follow the format and ensure ALL pics are present or I can't help.
Burberry authentication format and required pics here
LV authentication format here and required pics for authentication here
Required pictures, most likely, are: close up pics of stitchings, hardware, interior/lining of bag, any leather patches, Burberry logo, close up of where it's made from, maybe a close up of the beadings, and stuff like that. It's to help them determine if the bag is authentic or fake.
Hope this helps.