Generally speaking, what you are asking for is usually done via a hardwired connection if at all (BlueTooth usually doesn't provide storage access, only I/O such as headset/speaker, and to a much lesser extent - at least on cellular devices - text input).
But, because most phones provided by most of the providers (at least here in the NE) are deliberately crippled in various ways before the provider will carry them to force you to use services that the providers can charge for to perform tasks like those you are referring to, the answer is going to be phone and provider specific, and if you are looking for a "free" solution, will often will depend upon how far outside of the provider "approved" paradigm you are willing to risk going.
Since they aren't your phones, I'd talk to the provider first - they quite likely have a service that lets you send pictures from the phone for a minimal charge if they don't allow it via a direct connection.
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