Drag the gaps between tiles, or the gap next to the side panel, to resize. Double-click a gap to reset it. Sizes are remembered per layout.
Each tile shows how far behind the broadcaster it is, as reported by the Twitch player. Twitch's embedded player always resumes at the live edge, so the page can't hold one stream back to line it up with another. If one tile drifts or stalls, Reload all puts every player back on the live edge.
The players and chats are Twitch's own pages inside frames, so they use your twitch.tv login, including Turbo or sub ad-free playback. Firefox blocks this by default: click the shield in the address bar and turn Enhanced Tracking Protection off for this site, then reload.
Add ?c=channel1,channel2,channel3 to the URL to watch anyone.
?c=channel1,channel2,channel3