%1$s is using an older version of Telegram, so secret photos will be shown in compatibility mode.\n\n

Once %2$s updates Telegram, photos with timers for 1 minute or less will start working in 'Tap and hold to view' mode, and you will be notified whenever the other party takes a screenshot.
Appears when trying to send a photo with a timer to a secret chat with a user whose app is seriously antiquated. Not very realistic at the moment.