What does this equation mean?

The kill criterion follows directly from the same construction. If $\mathrm{RRR}(\pi)$ for NCP and CfC lands close to 1 — target convergence holding up once the color cue is reassigned to a decoy, at rates statistically indistinguishable from their own matched-appearance baselines — this critique fails outright, and the paper’s causal language should be read as exactly what its evidence, completed, would then support. If instead $\mathrm{RRR}(\pi)$ collapses toward 0 while a scripted, zero-training color tracker clears the same recolored-target trials at a rate no better than chance in the true target’s favor, the countermodel is confirmed and the causal claim needs the test it has been missing since publication. A third, intermediate outcome is honestly possible and worth naming rather than hidden: a partial ratio, say in the 0.3–0.6 range, would say the networks use color as one cue among several rather than the sole cue, and any drafted follow-up would need to say so plainly instead of forcing the result into either extreme.