Rooms often write to ask for a Friday sitting and attach a single screenshot of a green lamp. That picture tells us the lamp was green when someone pointed a telephone at it. It does not tell us what the bitrate did at 21:14.
We ask for forty-eight hours because most incidents hide in a day that looked ordinary. Encoder logs with timestamps, door-scan exports, handwritten occupancy every quarter-hour, even a duty editor’s notebook photographed page by page: all of these will do if the clock is on the page. Chat dumps without a clock, marketing decks, and password-protected folders will not.
If the sample arrives on Wednesday for a Thursday sitting, we move the slot. The pre-read is the cheaper part of the fee and the part that stops us wasting your ninety minutes on guessing. Send the messy log. We would rather read a stained notebook than a tidy chart with no minutes on the axis.