Tap this option to see the post appear as a sticker with a customized background for re-sharing in your Instagram Stories. The idea with the new re-sharing option is to give users a way to add their own commentary or react to a post, without repurposing it as their own - the way a regram (reposting to feed) feature would have permitted.
For privacy, there is a limit on the new feature.
Now it looks like that feature is live where users can now share posts of other Instagram users on their Stories. Moreover, if you have a public account, you can prevent others from sharing your posts to their Stories by heading over to the Settings Resharing to Stories menu. You can just add your own stickers, or text or doodle, whatever you wish to, and you are ready to post.
Instagram has made it easier for users to share any pictures and videos on their Instagram feed straight too Instagram Stories.
You can also rotate, scale or move the sticker around, and tap on it to explore other styles.
In a blog post, Instagram says that re-sharing can only be done from public Instagram accounts. The option also allows anyone looking at your story to see the original poster's username and go to their Instagram page. This is another effort by Instagram to increase the user's activity on Instagram by sharing more contents to more audience.
With the latest update, Instagram users can now share posts from their feed directly to their Stories as stickers. That would give Stories more prominence on the network - though not everyone is thrilled with their takeover.
At the moment the feature is only available on Android devices.