I’m not sure it has even been suggested, really. Viewers have inferred it mostly from Gus’ personal characteristics.
We’ve already been shown that. Recall how Gale’s murder when down at the end of season three? Mike was planning to kill Walt and most definitely did not expect what happened. He even allowed Walt to call Jesse.
There wasn’t one. Gilligan talked about some possibilities that they tossed around for establishing shots but couldn’t come up with anything. The house they shot in is actually in Albuquerque, so they couldn’t get a Houston skyline shot from there. They thought about somehow inserting a Texas flag somewhere but couldn’t decide on anything so they just let it go.
But he did say that she definitely does live in Houston.
Seems like it would be trivially simple to do a night shot of Mike driving his car under an interstate sign that said Houston this way or even a “Welcome to Texas” billboard out the car window. Might cost a couple grand, though.
I thought it was odd, and perhaps a conspicuous setup to show Hank suddenly interested in minerals and crystals.
Perhaps it is meant to payoff on a pivotal clue leading to the investigation, but I do recall Hank getting to show off his knowledge about the coloration of some pink quartz or something to Walt Jr. and Walt interrupting Hank with much deeper, scientific and chemistry related knowledge.
It seemed to humiliate Hank by the look on his face, but that was an odd introduction to his character if that’s all they meant to do with it.
We shall see. Look out for something to do with minerals or geology in episodes to come, that Walter might overlook, leaving behind a glaring clue to Hank.
ETA: perhaps in that sense, Hank underestimates Walt’s aggressiveness, and Walt may underestimate Hank’s “book-smarts.”
I just re-watched the episode in which Hank admits to what he did to Pinkman. It was really moving to see this kind of a depiction of an ethical law enforcement officer. Almost every TV and movie depiction try to show us that society is foolish if it expects cops to follow the rules.
I hadn’t considered that. I live a sheltered life. Well, more provincial than sheltered, actually. 
Now I’m back to thinking there’s no personal connection between Gus and Lydia, and that the child was there to soften Mike.
Gilligan said in the Podcast to 4.13 that NotGus was his “best friend, or even more than a best friend”. Not sure if it will be explored any more (I don’t see any reason to), but in the same ambiguous way he referred to Walt: “It certainly appears as if he poisoned Brock” - so in a way he did confirm it, even if it’s irrelevant.
Re: Lydia’s daughter speaking Spanish, she can’t even properly count to ten without help from her nanny, so I got the impression that she is just now learning to speak the language, as an ambitous mother might have her daughter do, especially in this region. If there is any Spanish connection to her daddy, he didn’t teach her.
Oh, one little detail that just jumped out to me on rewatch: Germans don’t eat tater tots, with or without Franch. 
It’s an international fast food conglomerate.
Those didn’t look like tater tots to me. Too smooth. It just looked like something fried.
ETA: I thought Herr Schuler’s wordless performance was amazing. Yeah, they probably made it wordless because the actor doesn’t speak German, but it was amazing writing and acting anyway.
Looked like chicken nuggets to me … which also would make sense if they have an opening in their stable of restaurants for a chicken place.
Again I bring up remembering Gus in a photo wearing a military uniform…anybody else ???
Yeah, I though they were chicken nuggets too.
I’d have to check again, but I believe it was mentioned in one of the behind-the-scenes featurettes (or maybe the podcast) that they were tater tots.
They were tots without a doubt. They were just like the flat, coin-shaped ones from Taco John’s.
By the way, I don’t know about you guys, but to me, when I see the name Giancarlo Esposito, my first thought is Buggin’ Out from Spike Lee’s Do the Right Thing – “Yo, man, your Jordans are fucked up!”. Seeing him as Gustavo Fring is just mind-blowing.
Tater tots. And according to the Insider podcast, the delicious sauces were actually frosting. Except for Franch, which was delicious, delicious paint.
Frosting? That’s disgusting. Poor guy. I wonder why they didn’t use real flavors – perhaps because they wouldn’t hold their viscosity under studio lights? But I suspect frosting would melt too.
By the way, does anyone have any insight on what actually happened between Walter and Gretchen in the past? It was never really all that clear to me why Walt broke up with her and left the company.
My suspicion is that it has something to do with Walter’s pride and arrogance, which is what always sends him over the edge and causes him to make big mistakes.
I just rewatched “Full Measure” and I see that Chow was the guy whom Mike saved from the Juarez cartel which was holding him hostage and forcing him to hand over supplies.
That was the scene in which Mike used balloons to knock out the power in the warehouse. Could that actually work?