What am I seeing?

[Chickensin_MA]

I put 6 eggs in the incubator on Sunday night. 4 look like this one, the other two look empty. What am I looking at here? Thanks!!

 

[Yorkshire Coop]

That looks like yolk. Can you see any veins?

 

[nuthatched]

They don't appear to be fertile

 

[Yorkshire Coop]

Good pics here for comparison for you ~ https://www.backyardchickens.com/ar...ion-through-incubation-of-chicken-eggs.47879/