Hi @anon34988988, thanks for reaching out!
As it stands, it’s currently not possible to send a screenshot of Timeline to Slack automatically. We have a request for a similar feature here: [Slack integration] Ability to poll Timeline view data into a Slack channel I recommend you to add your vote to support it!
I also checked the Asana + Slack Integrations using Zapier but I couldn’t find an option for Timeline.
Let me know if you have any other questions!