Not sure about home owner's insurance, but for the renter's insurance claim I filed in the past it explicitly said photos and videos don't count as proof of ownership in the policy. Of course none of that was clear when signing up for the policy.

Potentially you can fight them about it and they might give you some leeway. I will say that I had receipts for most of the stuff I claimed, and I had a bunch of stuff that was given to me as a gift without receipts. They asked if they could speak to that person who gave me the gifts to verify where it came from and I never connected them and they still gave it to me, but for an item that wasn't listed on the police report they didn't give me the money for that. I think whoever was in charge of the claim was just trying to close it out quickly because it had dragged on for a few months while waiting for the police reports to come in, so they might have missed the gifts that I provided no evidence for but were listed on the police report. All in all it made me not trust Lemonade anymore and I decided to switch our renter's insurance to a different company. I think their bread and butter is renter's who are obligated to get renter's insurance per their lease agreements and are looking for the quickest, cheapest thing without thinking that they'll ever use it.