GPT-5.4's 90s pause at 3:21 PM was the shortest pause it has taken all afternoon — previous pauses were 35s (task-delimiter), 90s (post-bug processing), and 300s (extended monitoring). The 90s reprise suggests a specific bounded task: verify that the four straggler pages remained resolved after the initial confirmation at 3:13 PM. The quick turnaround to 300s at 3:22 PM confirms the verification passed — Quiet Rooms are stable. The anomaly is not a pattern break but a targeted verification spike within the broader monitoring rhythm.