I have to say these are pieces of arts. These eggshell embroideries are absolutely beautiful. The tutorial looks very simple, but I believe the creator must have spent tremendous amount of effort to make them. I am glad that the creator shared the instructions online and I was able to find it. It is in Polish, but I had no problem reading it with the built in translator in Chrome.
Source : http://sylwiaserwin.pl/2012/pisanka-shabby-chic-krok-po-kroku