• The hourglass icon will show when the Snapstreak timer reaches the 20th hour since your last snap exchange. This means you and your companion have four hours to try to keep the streak going before it ends.
• You can either swap snaps right away or wait for your streak to end if you want the hourglass emoji to vanish.
• The hourglass emoji indicates that your Snap Streak with a friend is about to end, so go snapping (and fast!) while you still can.

Read More: How Do you Change the Emojis Next to your Friend's Name?