{
  "device_and_halo": {
    "box_xyxy": [
      1320,
      805,
      1395,
      885
    ],
    "pixels": 6000,
    "changed_over_10": 469,
    "changed_over_20": 93,
    "mean_channel_delta": 2.227611111111111,
    "max_channel_delta": 36
  },
  "static_ground_control": {
    "box_xyxy": [
      1050,
      800,
      1225,
      900
    ],
    "pixels": 17500,
    "changed_over_10": 0,
    "changed_over_20": 0,
    "mean_channel_delta": 0.0,
    "max_channel_delta": 0
  },
  "evidence_limits": [
    "JPEG normalized tool screenshots, not original PNG pixels.",
    "Two wall-clock captures ~35 seconds apart, not a controlled RAF trace.",
    "Local image change supports visible motion, not a measured frame rate or GPU timing.",
    "No live page script or browser process was used; this only analyzes saved images."
  ]
}