I wonder the same. When you get the eggs shipped you don't know for sure how long the seller has had them and how they have been cared for. I will say that my BLR eggs looked awesome when I candled before putting in bator. My blues, I didn't feel the same, kinda looked clear but I don't have a clue as for sure what I'm looking at. The BLR eggs looked like you could see the yoke which I think that is what your looking at...lol I just know come day 7 and I see it moving I will be happy!
I hope your new eggs do great! I candled my big batch of Seramas last night... and I believe I have 7 clear, 4 quitters and 17 developing! 17 tiny eggs : )
This one I have trying to pip today... this egg I can see shake with every single peck... for days now... pecking to pip internally and pecking to pip externally now. It is giving me a new appreciation for how hard they have to work to hatch. Endless hours of pecking! I see why they have to rest for a day once they pip out.