Mastodon's desktop site has two different interfaces: single column (like Twitter) and multicolumn (like Tweetdeck)
You can switch between these interfaces by going to:
Preferences > Appearance > Enable Advanced Web Interface
(selecting this activates multicolumn, unselecting activates single column)
Multicolumn has four columns by default, but you can add more, which may suit people with very wide monitors.
Pony fag art.
Pone.Social is a Mastodon-enabled social network for bronies, pegasisters, and all the rest of you horsefucker degenerates.
As long as there are at least two of us talking about ponies, the ride will never end. 🎢