It is possible to recover data (pictures, videos, contacts, notes, etc.) from DEAD devices, whether they are iPhones (iOS devices in general) or Samsung phones (Android phones in general, such as Sony, LG, HTC, Motorola, etc.).
You have to take or send your dead device to people who specialize in data recovery from hand held devices. I am not talking about big/reputed data recovery companies as those are mostly specialized in recovery from failed drives, not from hand-held devices. It's a completely different science.
Also don't take them to people who do general repair or even microsoldering repair but are not experienced in data recovery. In this case the science is the same, but the approach for data is completely different in order to preserve and recover data.
We've had iPhones come to us after going to 1-2 and a few times to 3-4 different repair techs and all failed to recover data, and pronounced the devices dead and unrecoverable; and we could do it under an hour. A couple of times we even gave back working devices. So choose wisely who you should trust your device with specially when it comes to data.