A face that means "explain this"
The Jackie Chan confused reaction is a still of him looking genuinely lost: eyebrows up, mouth not committed to a word. It circulated as a reply image, often labeled as a "what" face, for posts that do not deserve a typed answer. The power is that the expression is specific. It is not anger and it is not a laugh. It is the pause before either.
Why this still won
Plenty of celebrities have a puzzled photo. This one won because the crop is tight, the expression reads at a small size, and it does not depend on a subtitle. You can drop it under a screenshot and the reply is finished. That is the whole job of a reaction meme: replace a sentence everyone was about to type.
People use it for bad takes, for plots that jumped a step, and for the moment a plan stops being a plan. It stuck around because those moments did not go away when the apps changed.
The shirt
The Jackie Chan WTF tee is that pause, wearable. It sits with the other scene reactions in the movie collection. If the design you want is the mood and not the movie, the mood collection is the neighboring rack.