Snapchat has a feature called Story Replies that aims to facilitate further interaction between users. This tutorial will teach you how to use Story Replies to respond to individual snaps in a user's story.
How to reply to a Snapchat story?
In order to take advantage of this feature, you must be currently viewing a user's snap story. When the image or video of interest appears in a user's story, simply swipe your finger upwards on your screen - you will be able to write your reply.
How to reply to a Snapchat story with a picture?
If you want to reply to a story with a photo, then just swipe up! This will start a conversation with the user and it will allow you to send them a picture.
Snapchat story reply not working: what to do?
Sometimes the app crashes and your Snapchat story reply gets a "failed to send" message. If this is your case, then you should know that there is one simple trick that seems to work almost every time: just log out and then log back to the app!