In a recent update to the app, Slack added the team switcher panel to the left-hand side of the interface, allowing those with multiple teams to conveniently switch between them. This latest release hides this by default if you're only part of a single team.
It was fairly annoying to have the team sidebar present when you only had access to a single team. Here's the change as detailed in the 2.0.6 changelog:
"After an outpouring of consternation regarding the team sidebar, we've listened, thought hard, and removed it. Those signed into a single team will find the sidebar hidden once again. It's as if we never changed it! Or rather, it's as if we changed it, and then changed it back. In fact, it's EXACTLY like that."
Enjoying the update? Let us know how you're dealing with the change in the comments.