{
  "video_id": "knaLhBVLRWg",
  "observed_date_utc": "2026-10-06",
  "analysis_date": "2026-10-07",
  "scope": "One signed-in desktop Chrome account, one Short and one channel Shorts grid layout; estimated source crop, not a platform specification.",
  "source_A": {
    "sha256": "df291633555bb693404379f932a22ba614b4dcd28afdad0cebb7c0246069696f",
    "size": [
      1080,
      1920
    ],
    "decoded_frame_seconds": 2,
    "url": "/shorts-samples/cover-input-a.png"
  },
  "screenshot": {
    "url": "/shorts-samples/channel-card-a-desktop.jpg",
    "sha256": "33fa9c89f09d1fa943ebff84f8154dfd044bdd024c3ccf86b1fe3aab04c26748",
    "size": [
      1439,
      904
    ],
    "observed_at_utc": "2026-10-06T14:08:56.891Z",
    "kind": "Unmodified original desktop channel screenshot; A static card in saved-B phase"
  },
  "screenshot_card_bounds_xyxy": [
    307,
    317,
    478,
    573
  ],
  "card_size_screenshot_pixels": [
    171,
    256
  ],
  "best_fit_source_bounds_xyxy": [
    0,
    150,
    1080,
    1770
  ],
  "estimated_retained_source_size": [
    1080,
    1620
  ],
  "estimated_total_vertical_fraction_removed": 0.15625,
  "snapshot_count": 5,
  "distinct_decoded_card_images": 2,
  "method": "Bounded source-crop search; resize with Lanczos; threshold RGB sum >450; compare light ink within card, excluding top20px and3px borders.",
  "assumptions": [
    "Full original width held fixed; search limited to vertical crops.",
    "JPEG bounds manually read; pixel rounding limits precision."
  ],
  "samples": [
    {
      "sha256": "d133b80097ce9668e0a2f10afae10236bcb9feba74f454f56df467f717770c61",
      "observed_at_utc": "2026-10-06T14:06:06.688Z",
      "screenshot_size": [
        1439,
        904
      ],
      "decoded_card_rgb_sha256": "811684c2daa6f847e738b6ae64697fc85aa63b19549a56c2aa67146d8494b8fb",
      "crop_ink_mismatch_fraction": 0.013655872024970737,
      "full_frame_stretch_ink_mismatch_fraction": 0.0734035635323189,
      "wrong_B_ink_mismatch_fraction": 0.16043698790479907
    },
    {
      "sha256": "36a690f23c53ee060a895cbe736447970b4b7ef1d4e21ce3d75449faaaccdfcb",
      "observed_at_utc": "2026-10-06T14:06:53.087Z",
      "screenshot_size": [
        1439,
        904
      ],
      "decoded_card_rgb_sha256": "811684c2daa6f847e738b6ae64697fc85aa63b19549a56c2aa67146d8494b8fb",
      "crop_ink_mismatch_fraction": 0.013655872024970737,
      "full_frame_stretch_ink_mismatch_fraction": 0.0734035635323189,
      "wrong_B_ink_mismatch_fraction": 0.16043698790479907
    },
    {
      "sha256": "3e3e065c5f3692e707cbfa3b06fdd67fb6fc46dc1d3a0422a85d1c0b183fd992",
      "observed_at_utc": "2026-10-06T14:08:23.517Z",
      "screenshot_size": [
        1439,
        904
      ],
      "decoded_card_rgb_sha256": "811684c2daa6f847e738b6ae64697fc85aa63b19549a56c2aa67146d8494b8fb",
      "crop_ink_mismatch_fraction": 0.013655872024970737,
      "full_frame_stretch_ink_mismatch_fraction": 0.0734035635323189,
      "wrong_B_ink_mismatch_fraction": 0.16043698790479907
    },
    {
      "sha256": "33fa9c89f09d1fa943ebff84f8154dfd044bdd024c3ccf86b1fe3aab04c26748",
      "observed_at_utc": "2026-10-06T14:08:56.891Z",
      "screenshot_size": [
        1439,
        904
      ],
      "decoded_card_rgb_sha256": "811684c2daa6f847e738b6ae64697fc85aa63b19549a56c2aa67146d8494b8fb",
      "crop_ink_mismatch_fraction": 0.013655872024970737,
      "full_frame_stretch_ink_mismatch_fraction": 0.0734035635323189,
      "wrong_B_ink_mismatch_fraction": 0.16043698790479907
    },
    {
      "sha256": "1c810c45ed8510a6f5bb72dea792320853d9a9f10f0154898e3b0b9b2cde7a04",
      "observed_at_utc": "2026-10-06T15:27:57.636Z",
      "screenshot_size": [
        1439,
        959
      ],
      "decoded_card_rgb_sha256": "8a56601dad3b7a08a9de80fbbe45bbd4fd6afb5c078e30369aef3af817fe390f",
      "crop_ink_mismatch_fraction": 0.015268565483157758,
      "full_frame_stretch_ink_mismatch_fraction": 0.07392378722850826,
      "wrong_B_ink_mismatch_fraction": 0.16038496553518014
    }
  ],
  "limits": [
    "Five snapshots contain only two distinct decoded card images from one account/Short/desktop layout, not five independent experiments.",
    "Manual JPEG bounds, rounding, resampling and video compression limit coordinate precision.",
    "Best-fit coordinates are estimates; about150 source pixels per vertical edge, not exact device coordinates.",
    "Displayed cards are A even in the saved-B phase; no B-card crop measurement.",
    "No phone measurement, synchronized capture, platform-wide ratio or causal/cache claim."
  ]
}