I sent a client an HD video, created at the customary HD 16:9 aspect ratio.
Client: Please send me a 4:3 thumbnail of the video.
Me: Okay, sure.
I cut a 3:4 thumbnail out of the 16:9 one and sent it.
Client: I can’t see the whole screen! Please send a 4:3 thumbnail that preserves the 16:9 aspect ratio of the video.
Me: Okay sure.
I letterbox the thumbnail so the total image is 4:3 but the 16:9 aspect ratio of the video is preserved.
Client: Great! Now can you just make the image a teeny bit taller on the top and bottom to get rid of the black bars?
I resent the 16:9 thumbnail. The client had no further requests.