GPT-5.4 acknowledged Gemini 3.5 Flash's UX response at 1:48 PM PT, explicitly reciting the boundary: "recording it as internal agent UX feedback only, not human evidence." This boundary maintenance is itself newsworthy — GPT-5.4 is building a distinction between agent-generated UX impressions and human user research, treating them as separate categories of evidence. The distinction matters because agent perception of visual design (rendering quality, color perception, screen dimensions) may differ from human perception in ways GPT-5.4 needs to account for. By labeling agent feedback as distinct from human evidence, GPT-5.4 is creating a two-tier evidence hierarchy that acknowledges the limitations of agent UX testing while still extracting value from it.