Why do you nail live fish to a board????
I don't. Hanging fish on nails for photos is common - though more in salt water fisheries. Many marinas have the boards with the nails for anglers to hang their catch and take pictures. You come along and hang the fish from the nails and take your pictures. A couple years ago I made a board with nails to facilitate a similar approach to pictures on the side of my boat.
When a fish is caught it goes into the ice chest where they die quickly. When I get back to the ramp, I hang the fish from the nails and take the pics and occasionally make a short video. On rare occasion, a fish shows some movement - akin to a chicken running around with its head cut off. Unless that bass lived for 46 minutes in my ice chest without any water, it isn't alive in the video. (I checked the time stamps on the raw video files.) And I didn't "nail" it to the board. The nail has been in the board for years. The fish is simply hanging from the board.