Its just a little extra calcium deposit. No biggie. Its just part of getting the kinks out. Like everything else with chicken eggs, one odd egg is not an indication of a huge problem.
If you want to read up on the weird eggs this is a good page...
If you are interested in how the egg colors come out with EE's this old thread does a decent job explaining the colors.
https://www.backyardchickens.com/t/720118/ee-egg-colors