One accidental tap, and it is already sent
A single tap captures your photo and sends it straight to your followers. There is no pause and no way back. Accidental taps happen all the time, so a tiny, low effort gesture is firing off something high stakes and permanent. Nielsen's third heuristic asks for a clearly marked emergency exit: an undo. Instant has none.
Today: a tap captures and sends in the same motion, with no confirmation and no way back.
A five second grace period, with Undo
Keep the speed, add a safety net. The moment something sends, a quiet Undo button appears for five seconds and then fades. Nothing about the flow slows down, but a slip is no longer permanent: the emergency exit the heuristic asks for, without a confirmation dialog getting in the way.
Redesign: a short, calm window to undo a send.
An action you cannot take back should never be this easy to trigger by accident. Always leave a way out.