A blindfolded guesser stands in front of a line of strangers, and you cannot help playing along. Could you tell the languages apart yourself? The game is clear in one glance, and the only way to check your guesses is to watch.
How the packaging works
Title
The title names the game and hints at a repeatable series.
Thumbnail
The image stages the guessing game, blindfold, contestants and all.
Remix this
If your subject can become a guessing game, stage the game in the image so viewers start playing before they click. If you teach, testing the viewer beats telling them.
The transferable lesson
Stage a game viewers start playing before clicking
What to avoid copying
The eight faces work because the format is a lineup; in most thumbnails that many people is clutter.