Actually you guessed it, I was thinking about IRC while I was drawing it! :)

(and I don't think it lost for that reason)

I am absolutely in favor of spacious interfaces, in fact as you can see between messages there is more space than any other application. But on a mobile we can't ignore the small space, so other solutions like using the full width and compacting not so useful information (progressive disclosure approach) can help.

I did not say it is better, I asked for opinions. This is just a mockup and lacks the whole interactive and feedback part, which is critical to verify usability, so your idea of self-explanation cannot fully work here. Insights and feedback are important before proceeding with development, we are here to share, if you want to join you are welcome.