Do photos, videos and documents wait for signal too?
Yes. A photo, a video, a voice recording or a document you attach waits in the outbox with the rest of the record and sends itself when you are back online — a photo still marked with where it came from. The limit is 150 MB for one upload and 500 MB waiting on the phone at once; anything larger tells you to send it again with signal.
From the guide Working offline.
What is held, and for how long
Anything you typed, and any file you attach — a photo you took in the app or chose from your library, a video, a voice recording, a PDF or another document. An inspection photo, a video of a leak on a repair request, the paperwork for a housing program and a site check-in all wait with the rest of the record, up to 150 MB in one upload and 500 MB on the phone at once. Only something larger than that fails in front of you rather than waiting, because holding it could fill the phone; the app says so, and you send it again once you have signal.
A file that waits is sent over whatever connection you have when the signal comes back, exactly as it would have been sent at the time. If you would rather a large video went over Wi-Fi, discard it from the outbox and send it again when you are on Wi-Fi.
A few tools need an answer while you are looking at them, so their uploads do not wait: reading a floor plan from a walkthrough video, scanning a receipt, and the other drawing tools in the floor-plan editor. Saving the floor plan itself still waits.
Read the whole guide: Working offline