I’m not against the no picture policy, but “drowning the nigiri in a pool of soy-wasabi paste” is different.
It’s similar in that it’s the chef’s house rule, but an instruction against overapplyiing condiments is qualitatively different than a no photo policy.
“Drowning” sushi in wasabi soy makes it unbalanced and ends up erasing any distinction for what made ostensibly good sushi in the first place. The nigiri falls apart and the rice becomes too wet and too salty. The neta’s flavors, which are often delicate, are almost certainly going to be washed out. It effectively lays waste whatever good sushi there was to begin with and diminishes one’s ability to appreciate what’s being offered. Even if the diner doesn’t know or care about the textures or flavors, or even likes extra soy wasabi, drowning the sushi may be perceived to some extent as a disregard for the chef’s skills, as if to say that the sushi needed some real correcting.
On the other hand, nothing about taking a picture - particularly if it’s done quickly and discreetly - necessarily diminishes the food presented at Vespetine, or wherever. A picture can be taken in literally two seconds, and it does not really detract from one’s ability to enjoy the food as presented. I could imagine that the no photo policy is more about not spoiling the surprise for others, or rather to reserve knowledge of the food experience to those who have the ability to be affected by all of the other aspects - the music, the architecture, etc .
I think both rules are fine, but they are nonetheless different.