I've seen eggs like that. It's extra calcium that seems to stick all over the egg shell. I wouldn't worry about it. Sometimes you can rub the egg shell with your finger and it comes off. Also, sometimes that happens and the egg shell is very brittle and thin. I have seen these at the end of a season, or the beginning of a new season.
I have one hen out of 6 that has always layed eggs like this, fantastic layer daily but very poor shells ,often porous and very rough with half brown and white the other end and she lays soft shelled eggs aswell,she is a goldline hybrid and the others are all different hybrids ,however all has same lifestyle,diet etc and happy hens so never known why she does this as used to worry she was poorly or lacking something but been 2 years like this now?
I've got one of my four hens doing this now.. Just started this week. All the hens are free range and have calcium available at all times. The chicken appears healthy and other than the roughness and discoloration the shell is hard and thastes fine. It's good to know others have encountered this so I don't feel worried..