Sent off letter, picture, and SASE to Brad Bird on May 13, 2018. Received back an 8x10 preprint and a typed letter (personalized) from Pixar Studios- they kept the picture I wanted signed but sent back the letter I wrote to Bird. The address I used was: Brad Bird Pixar Animation Studios 1200 Park Av...

Sent 5/13/2018, received RTS (insufficient address) 5/28/2018; address used:

Kristin Chenoweth
Micone Entertainment Group, Inc.
1804 Farley Road
Whitehouse Station, NJ 08889-5027

Sent 5/13/2018, received RTS (unable to forward) 5/28/2018; Address used:

Ms. Sutton Foster
Creative Artists Agency, LLC
162 5th Avenue
6th Floor
New York, NY 10010

I received the same autograph from Tim a few weeks ago and I believe it is authentic. A quick search on Google shows that's how he always signs his name. It could be his secretary, but I think it's from him.