You reply from Slack, HipChat or Telegram
When you send message in Slack, HipChat or Telegram it will be sent to the last visitor who sent you message.
You need to add @visitor_id to your reply only when you are chatting with several visitors in the same time and want to send message to specific user. As soon as you send @visitor_id this visitor becomes default visitor and next messages can be sent without @visitor_id.
There are commands you can use
Send this command to get screenshot from browser of current visitor you are chatting. This feature is available if visitor uses modern browser.