Talking to a desk works the same everywhere: a message becomes a turn, a slash command is answered by code, and a message sent while the desk is working steers the running turn. Talking to a desk explains it. A desk can also ask you a question, show you a plan, or wait for your permission before certain actions, in the web chat, the terminal and on Telegram alike; Questions, plans and permissions explains how.
The orange dot is a message going in through the gateway to a desk; the blue dot is every step of the desk's turn coming back as events, to the page and to every other listener such as the journal.