Twitter's updated "quote tweet" is now rolling out for iPhone and on the Web, with Android to follow.
The feature allows you to embed and comment on a tweet within your own tweet, and to do so at the click of a button.
To use the feature on the web, hover over a tweet, click the retweet icon, and add your comment in the pop-up "Add a comment" field before clicking "Tweet."
From mobile apps, tapping the Retweet icon will give you the option "Quote Tweet," where you can then add your comment.
Watch the feature in action