They have the microphones placed very close to the speakers, which can largely account for the difference you are hearing relative to other YT videos. This fact will also go a long way in minimizing the contribution of room reflections, creating an advantage that you wouldn’t experience were you there in person.
What’s largely masked in that YT recording is the box resonances (“warmth” to some listener’s ears) that are prevalent in AN speakers. AN essentially claims they can integrate those resonances such that they enhance the bass and dynamics, rather than serve as a distraction. IME, they don’t manage to achieve that goal any better than do the thin-wall BBC legacy brands (Harbeth, Spendor, Graham etc). If anything, I found their cabinets to be more lively and distracting than those aforementioned brands, despite the fact they produce tighter/drier bass. To me the AN-Es sounded as though they’d actually benefit from using thinner cabinet panels and less stiffness. That might lower cabinet resonances to a lower frequency band, making them better integrated with the bass.
Overall, the ANs sound how I would expect a speaker to sound if someone were to simply pick some mid-tier Seas drivers and slap them into an undamped plywood box with a first-order crossover. In other words, they sounded like what a novice speaker designer would achieve by merely playing with decent drivers in a garage-constructed box. Sometimes such designs can sound surprisingly respectable for the mere fact they have decent drivers.