^ the thumbnails are definitely a diff image file now; the steal, sex-up & re-up bandits are expert at the enticing thumbnail images. AFAIK, in YT's older daze, they automatically took the center-most frame from the full duration of the vid (obviously with some default instruction if the vid had an even # of total frames), and that was the thumbnail. Now any image file the vlogger specifies can be the thumb; though I believe when the vlogger doesn't specify any image file for the thumb, YT still defaults to grabbing that middle video frame.

Back in the mid/late '00s when I paid attention to 911blogger.com, someone made an instructional blog there telling how to edit a 911T vid for YT uploading, where the center split-second of run time, was a still image of say, a hot babe or something enticing. Then upload with a misleading title, and in combination with what would appear as the thumbnail, you could reel in thousands of peeps who would then find themselves watching say, WTC7's CD, with commentary. At the center of the duration, that split-second sexy still image would flash by. 911Blogger user who made this instructional blog said a few obligatory words about the "ethical question"; and of course rationalized that this is an info war, after all... which I was sympathetic to, in that specific case. The (((JSM))) who the click-dupes got all their 911/warrenterra-hoax beliefs from, are knowing & premeditating deceivers, right? Fire with fire; ethics rules is for fools, when the opponent/enemy ignores them!