Hi girls. That’s only partially the case. I mean, we obviously have a common design of what a Tweet looks like at Twitter, and the new timelines are an implementation of that design, but the widgets do implement two variations already (wide and narrow mode at < 320px width) to try and be more adaptable to the web.
The issue with going thinner than 220px is the amount of line wrapping that occurs around user names, and the legibility of the line length of the Tweet text itself. Making the avatar even smaller only buys a few pixels before they become indiscernible, and removing avatars would compromise the representation of user’s identity (especially in the case of recognising Retweets in the timelines.)
All that said, we’re keeping an eye on how people get on with the constraints as they are, and could revisit it if there’s a common problem. What’s the column width you’re trying to work with?