What the traveler told the Help Centre it had wrong about them, keyed by the fact. The Help Centre asserts four facts at the top of every screen (phone, where they are, departure, eSIM state); three of them are correctable, and all three are asked at once in a single sheet. The correction is scoped to that Help session and nothing is written back to the account, so the conversation is where it becomes durable.
Sent as a disagreement, never as a fact — the context attached server-side (phone_os, device_model) still reports what the platform holds. "Traveler says Samsung, our record says iPhone" is worth more to an agent than either alone. Omit the field entirely when the traveler corrected nothing; an empty object reads as "they were asked and said nothing".
Keys: device (iphone | samsung | pixel | xiaomi | other), location (not_there_yet | in_destination | trip_over), esim (not_installed | not_connected | working). Reaches Intercom as the traveller_says conversation attribute.
device names a phone brand rather than a platform because the brand is what decides which instructions and artwork exist — the Samsung, Pixel and Xiaomi Settings paths differ from each other and from Apple's. other means generic Android.