You can now like individual comments. This shows appreciation and/or agreement. This means that you can now interact with posts in a similar way to Facebook without having to go to the hassle of posting a comment and notifying the world that you think someone has a 'nice car laaaaaad'
So in the past, nobody would respond to this message unless they felt strongly. But you can now just click the thumbs up or thumbs down below without needing to leave a comment.
Doesn't work in tapatalk unfortunately. But does work in your normal PC browser.