Well none of my eggs are close enough to show a clear pocket yet, and my phone take bad pics in the dark so this is the best I could do.

Here's a pic to show the pocket area I just took. It's the pointy end of the egg. Sometimes it's hard to find. I try to use an actual candler or a small flashlight.
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Though it's a terrible pic you can still see the dark yellow of the yolk and veins.
I snapped this pic of a hatched egg actually, but it's the same sort of thing. The duckling just hatched an hour ago so the shell is still pretty moist and accurate.
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See how there's that light yellow color and no veins? Just some stringy broken veins that are no longer active. That is how it'll look in the pointy end when it's ready. I'll keep watching my eggs and try to catch one right before hatch.