Optional
Each written surface's element, so a caller can address it in content — the imagery export textures these (§15.5). Optional only so adding it is not a breaking change to a published result type.
content
Why nothing could be written, naming what the source does contain.
Each written surface's element, so a caller can address it in
content— the imagery export textures these (§15.5). Optional only so adding it is not a breaking change to a published result type.