It would simplify life for users that work a lot with photographs to have the "Copy Key Frame Attributes" include Duration in the copy. It has no meaning for video and should be ignored in that case, but I often have two operations to perform when I bring an image into the timeline with the intention of making it perform exactly as another image - first set duration then copy keyframe attributes.
If I copy keyframe attributes first and the duration of the new image is shorter, the new image's attributes will be missing keyframe attributes that don't get copied and will have no attributes set at the end of its frame.
If the duration of new image is longer, it will have no attrubutes beyond the last attribute in the copied image. Paul C