This was south California casual, I guess? Shoes that look good sockless (or wear those little liner socks). Button-down shirts that have some simple design. It was nothing really, and I'd have no problem doing outfits that good myself now, after spending perhaps 10-15 hours reading about fashion and trying stuff out. But at the time it was revelatory.
I am certain that many guys in my position would do fine just going any decent-looking clothing store and asking the salesguy to make you look OK. They're good enough to not let you leave looking like a dweeb. Personally I like some of Banana Republic's stuff, as it's higher quality than Target, and still casual (yet the other half of the inventory seems very "douchy").
People are so vulnerable to social manipulation via clothing and all sorts of other means. The stereotypical programmer person looks down on this, perhaps because they're not comfortable, or because it feels "fake". It might be useful to view social as just another system to be hacked. And in the process, one might realise it doesn't have to be fake and can be quite rewarding.
Yes, I know, this reeks of just blindly following trends and conformity. But we don't say that of other hacks. "Loser! You just shoved some escape characters into a querystring and looked for issues. That's so common, you're such a sheep." Yeah, maybe, but the end result is what matters. And feel free to A/B test versus wearing a "I'm too CSSy for this shirt" tee and decide which leads to a more fulfilling experience.
[The irony of me giving out fashion and social advice. Like someone advising you to "buy a computer with Internet; that's my favourite program".]