The regular size egg is in the center, it's hard to tell but the big egg is most likely a double-yolker and pretty much fills my hand.
I have an assortment of chickens, mixed and matched over the years, with new ones added to the coop every so often. I thought I'd pretty much seen everything there is to see with eggs; ones with no shell, wrinkled eggs, half shell eggs, HUGE eggs, small eggs.... but then these gals do something that surprises me.
I've seen eggs that were small, or so I thought, but I have never, ever, not in my whole life, seen an egg this small come from my coop! The youngest chickens I have are about three months old, hens don't start laying until about five months, so I'm pretty sure this egg didn't come from any of them, but you never know.