The glyph/code spells out MULTI.

Astrid: How about we go for a walk. You know you haven't eaten in hours. The cafeteria's just downstairs. I think I saw tapioca pudding on the menu.
Walter: I can't deny I'm hungry.

Walter: A long time since I've seen the classic fruit cocktail. Why do you suppose that is?
Astrid: I suppose loading fruit with sugar, artificial flavors, and dyes has fallen out of flavor.
Walter: That's a shame, isn't it?

Walter: Forgive me if I'd like to spend my remaining time with my son.
Astrid: Well, what about Olivia? You saw how hard it was for her to leave him, but she's out there trying to find a way to end this.
Walter: I too have tried. I went so far as to ask God for help. How did he respond? Nothing.
Astrid: That's your excuse? Come on now. What have you done, Walter? God helps those who help themselves.

Sam Weiss: I’m not the first Sam Weiss.
Olivia: So which Sam Weiss is this?
Sam Weiss: My great-great-great-great grandfather. He was digging for mastodon bones and he discovered an ancient manuscript instead.
Olivia: So he was the one who wrote the First People book?
Sam Weiss: No, that was the fifth Sam Weiss. The third and fourth Sams spent their lives searching for the manuscript’s missing sections.
Olivia: You’re a dedicated bunch.
Sam Weiss: A machine with the power to create and destroy worlds shouldn’t be taken lightly.

Walter: That's it. Come and get me! Strike me down, you sprites, you elves, you glorious blue jets!

Walter: I know what it's like to feel unequal to the task required of you. To feel incapable. I'll never be the man I was, but I've come to embrace those parts of my mind that are... peculiar and broken. I understand now that's what makes my mind special. I wish you could see yourself the way I see you. You have no idea how extraordinary you are. If you're going to embrace that, there's no end to what you can do.
Olivia: I know that you want to believe in me. And I want to believe in me... but believing doesn't make it true.

Walter: Do you know me?
Peter:I know you’re not the Secretary of Defense. The sweater’s a dead giveaway.

The Observer can be seen in the crowd behind Peter as he asks the man on the street about nearby pawnshops.