Google did quite a bit of work on the phone dialer on the Nexus 5 and they’re looking to keep integrating improvements for the foreseeable future. The next item on the list according to a recent Google+ page will be to automatically pair your phone number with your Google+ profile photo. This would allow other people (presumably with Android phones) that that you call to automatically see a picture of you from your G+ page. Whether that’s a good or bad thing remains to be seen, but it’s happening regardless.
By default, all users are opted into this, which will actually start happening sometime in early 2014. Since this sort of sounds like it’s integrating into the Nexus 5 dialer, we may or may not see this on every available phone or Android version. This probably isn’t going to be the last you hear about it before it’s put into action, so we’ll keep you updated.