You hold up a card during a call and the words look backwards in your own video tile. Flipping the card image in an editor seems like a quick fix. First, check whether anybody else sees the same problem.
A self-preview can behave like a mirror while the transmitted picture remains correctly oriented. Zoom describes its mirror-preview setting as changing only how you see your own video. That specific behaviour should not be assumed for every app or camera utility.
Ask someone to read the card
Make a simple test card with a short word and an arrow pointing to one edge. Before the meeting, show it to a willing participant and ask them to read the word and describe the arrow. Avoid asking only whether the picture “looks right”: an ordinary face is a poor orientation test.
If they can read the card normally, leave the source image alone. Change your preview setting if that makes presenting easier. Altering the original to correct a local mirror can make the other person’s view wrong.
When the other person also sees reversed text
Confirm which camera the meeting app has selected. If a camera utility or virtual camera sits between the physical camera and the call, inspect its horizontal-flip setting too. Change one setting, repeat the card check and keep track of what changed.
For slides and documents, sharing the actual window is often clearer than pointing a camera at a page. Preview the shared content and close unrelated material first. If you plan to record, check a short sample recording separately; the participant’s view does not establish how every recording layout will look.