In order to use the filters, one will have to use the Twitter app, and not 3rd party apps. I always found part of the incentive to use Instagram is the social network. I wonder if Twitter use will go up for some with the ability to alter the filters directly in the app. Regardless, this move is a defensive move that puts Twitter on par with the abilities of Instagram. It makes Twitter, not a leader, but a follower. Will Twitter take ideas from other social networks, when it feels threatened?