One of our guests left us with some eggs – caged eggs.
I thought it was absolute fascinating to see the difference in eggs when I put some of ours into the egg carton too. Keep in mind that our chicken are mostly ex-battery hens that once used to produce those cage eggs. They were not considered good and productive enough for the batteries and hence would have been culled if we had not taken them.
I am just so glad they can still live a happy life.
Please if you can do one thing for animal welfare: Stop buying any of those cage eggs. If you like some more information, please have a look at Battery Hen Rescue and Rehoming. I am sure you find many more search results on the web.