Meaning
A hand with the middle finger crossed over the index finger, the gesture people make while hoping for luck. It means “fingers crossed”: wishing for a good outcome, for yourself or someone else.
It suits exams, job interviews, test results and travel plans: “Interview at 10 tomorrow, wish me luck 🤞” Sending it back to a friend shows you are rooting for them. There is a playful old custom of crossing fingers behind your back while telling a fib, so in a promise it can occasionally be read as “just kidding.”