You can see how it works in the example I’ve created here using my own Twitter profile, where the field that was formerly empty now reads “Tweet to @charlie_white”.
Perhaps Twitter was hoping the small change would be implemented without fanfare, but keen-eyed user Jeevan Gill (@jsammy17) tweeted to Twitter CEO Jack Dorsey, asking him if this was a new feature. Replied Dorsey, “@jSammy17 as of today!”
Even though Twitter just introduced its new Activity tab to its user interface yesterday, for some reason the company decided not to publicize this subtle tweak. Maybe the company didn’t want to get in the way of the social gaming war now underway between Google+ and Facebook.
Even so, any attempt to stimulate further social interaction on Twitter is probably a good idea, especially given the increased competition it’s facing from Google.