Overall Ratings for this ep 1.94 million, 0.8/2 share among 18-49yos

Boyd: You get into their system, you make the connect so that we... you can get a look at Perrin's brain map.
Victor/Topher: I'm not up to this. I suffer from acute agoraphobia Or I plan to.

Topher: It's different. Yeah. Than L.A.... uh...
Bennett Halverson: Well, I suppose it would be. You probably have palm trees and tans.
Topher: We're four stories underground. Not a lot of photosynthesis.
Bennett Halverson: No, no, you're very pale. White. Pinkish-white. I mean... your skin... Your skin is like a pig.
Topher: Bennet Halv...
Bennett Halverson: Because it's pink. People assume that pigs are bad, but I... I love them. I like them.
Topher: I hear they make good pets.

Stewart Lipman: Perrin has to be at that Senate hearing in four hours, or Rossum will have our heads.
Adelle: To be clear, this little project is your problem, not mine.
Stewart Lipman: Well, I'll remind you of that when we're bunk buddies in the Attic.

Victor/Topher: Do you know how many...?
Real Topher: Shut up and work.
Victor/Topher: I'm already working. I wouldn't hold your breath on the shutting up.
Real Topher: No. I wouldn't.

Cindy Perrin: Where is he?
Echo: Gone. Something else is here.
Cindy Perrin: Oh, God. Doll-speak.

Victor/Topher: Who's your back door man?
Real Topher: We'll just pretend I didn't say that.
Victor/Topher: Yeah.

Adelle: Finding him obstinate?
Real Topher and Victor/Topher: Yes! This is so weird.

Title: The Left Hand

Two references -- The most obvious being Bennett Halverson's lame left arm, apparently a result of something Echo did as Caroline (possibly what made her become a Doll?), but also a reference to Matthew 6:03: "But when you give to the needy, do not let your left hand know what your right hand is doing"

Victor/Topher: Who's your back door man?

The term "Back door man" refers to a man involved with a married woman, generally while the spouse is away, using the back door as an entrance & exit to make the affair unobvious to the surrounding people who might warn the cuckolded husband.

Bennett Halverson: Because it's pink. People assume that pigs are bad, but I... I love them. I like them.
Topher: I hear they make good pets.

The Vietnamese Pot-Bellied Pig is a moderately popular pet.

The reference to Matthew 6:03: "Do not let your left hand know what your right hand is doing" is particularly applicable to the situation of this story arc, as the two Dollhouses are acting at cross purposes with neither knowing precisely what the other is up to.