The space itself is acoustically engineered
But with such precious aural merchandise, how do you optimize a cutting edge store for real-world use? Well they legit built a full, actual-sized, working prototype of the entire store in a warehouse in SoCal before breaking ground in SoHo, just to make sure they got it right. That's dedication, folks.
The materials themselves are a 50-50 split between "absorptive" and "reflective" acoustic surfaces. That means that half of the construction of the space is meant to reflect sound (giving that nice ambient reverb) while the other half is meant to absorb it, giving effectively no echo. What exactly are these materials? Well the floors are mostly concrete (reflective), while the ceilings have a ton of soundproofing absorptive foam. The walls are metal with perforations in them, backed by more of the foam, passing sound through and then absorbing it. This balance, perfected by famous industry production pros (more on them later), creates the ideal ratio of booming, live sound, and clear, studio-quality spatialization.