V-JEPA 2 probe uncovers physical structure

This is a smart attribution-aware probe: freeze the encoder, keep the bottleneck lightweight, and the burden shifts from probe capacity back onto representation quality. The result is promising, but the authors are right to frame it as Stage 1 evidence rather than a final read on physics in latent space.

• –The chi-squared, MI, and JSD results are strong enough to matter, so this is not just a prettified clustering exercise.
• –The biggest separation along temporal structure fits V-JEPA 2's predictive bias better than morphology does, which is a nice internal sanity check.
• –The "one dominant codebook entry" pattern suggests a compact latent manifold with graded semantic shifts, not clean category borders.
• –Kinetics-mini proxy confounding, token-level pseudo-replication, and K=8 all weaken the causal claim, even if they don't erase the signal.
• –Stage 2 only gets interesting if larger codebooks and stronger nulls preserve the effect.