Hooray for the LinkedIN sign up/in integration via Janrain.
One of the key reasons to implement this feature is to automatically import data into Ning and thus reduce the effort needed to have a profile on "yet another social network."
When a user signs up for a ning community using LinkedIN (assuming you have a photo field set up in custom fields), the image that is imported from LinkedIN is very small, perhaps 80x80.
Ning displays this imported image at a much larger size (184 x 184) and they look terrible- pixelated, distorted, and just not what you'd expect for a professional integration.
The good news is that LinkedIN does have in its database much higher rez versions of the same photo, but Janrain/Ning need to import this version instead, or multiple versions.
I'm no API developer, so maybe the higher rez version(s) aren't available via Janrain. But I can say that this much-anticipated feature is pretty weak unless/until this gets fixed.
I doubt there are any hacks that an individual creator can do- but I encourage you to help compel Ning to get this right.
Updated after further testing: profile picture distortion happens with Twitter & Google sign in as well.