Your photos are your evidence
Why the app makes you take them live, and why that is on your side.
The photos are not the host checking up on you. They are the record that says what you found and what you left.
The arrival walk-through. Film it before you touch anything. If a guest broke something, or left the place in a state, this is the only proof that it was not you. Without it, an argument later is one person's word against another's — and you are the one who was there alone.
Before and after. Take the before photos when you start and the after photos when you finish. The app will not let you take an after photo before the work is done, and will not let you change a before photo afterwards. That protects the value of both.
Why you cannot choose photos from your phone. A picture from the gallery could be from any day and any place. The moment that is possible, no photo proves anything — including yours. Taking them live is what makes them worth having.
If something is already broken or missing when you arrive, report it straight away with a photo. Reporting it later always looks worse, however honest you are.