They have hardly tested every aftermarket cable on the market with LCD-3 (who has). This is what their sign beside HPA-21 said about the Toxic Silver Widow cable: "One of the most appreciated aftermarket cable for Audeze." They just wanted to show HPA-21 with really good gear.
I believe the Toxic Silver Widow cable is very nice. Comfortable. And since I managed to hear the low freq rumble on The Dark Side Of The Moon in the noisy environment I don't think it attenuates the sub bass, as my old (now unused) Q-Audio cable does. I'll probably buy a Toxic Silver Widow cable or two.
It's impossible to be objective about cables. Read reviews, forums etc. and pick one or two. I can only say one thing, if someone says that cables don't matter he/she hasn't compared the Audez'e stock cable with a good aftermarket cable (especially with a different sound signature) side-by-side. And that's fine too. At least for the wallet.