How to set a Google Plus photo as a contact-picture?

One of my _Google Plus_ contacts has some great photos from a recent family reunion I was unable to attend. I would like to use a number of these as contact photos on my Android device (Galaxy Nexus GSM w/ CyanogenMod 10.0). I have the latest Google+ app. Unfortunately there doesn't seem to be a way to DO anything with the photos, whether setting them as contact photos or saving them to the device. The Google+ app likewise does not show up as an option when setting a contact photo and choosing an app to select a picture with. **How can I set a picture from the G+ app as a contact photo?** I would like to set the pictures on the phone rather than from my computer because that way it keeps much higher resolution versions than setting them through the gmail contacts functions.