He continued, "I said, 'I want to meet with you because your offer was so lovely that I need to have time to explain to you why I'm going to say no'."
"And I did, and then they talked a lot."
After the show makers were done on their part, Stewart asked them to write everything down.
"And when I read them, I felt differently," he recalled.
Other members of from 'Star Trek Picard' cast were also present who didn't reveal a lot about their characters.
Alison Pill who plays a researcher only said that the character "gets into some antics."
Michelle Hurd is "part of an unrelated past of Picard's," and Brent Spiner who, as the show's first trailer revealed, will reprise his role as Data.
The new trailer of the upcoming CBS show was also unveiled at Comic-Con which featured a numbers of show's alums returning.
The first trailer was released in May.
'Star Trak Picard' is set to release exclusively on CBS All Access and will get an international distribution on Amazon Prime Video and on Cable networks Space and Z, in Canada, Variety reported.
Stewart, Alex Kurtzman, Michael Chabon, Akiva Goldsman, James Duff, Heather Kadin, Rod Roddenberry, and Trevor Roth are executive producing the upcoming show.
The previous 'Star Trek The Next Generation' series ran for a whopping seven seasons with around 170 episodes, which helped them earn 19 Emmy Awards.