I was taking grafts today from a friends hive that he started from a Jennifer Berry nuc a week or so ago - not a lot of drawn comb besides the original 5 yet. Nice mild mannered bees by the way.
Anyway the brood frame I was using had something - eggs, open brood, capped brood, a little nectar and pollen - in almost every single cell on the entire frame. A totally solid pattern. I also spotted a couple of cells that had many eggs in them - too many to count.
I guess this is just a case of a very prolific queen running out of room to lay and couldn't hold it any longer. Something I haven't seen before - that's not saying a lot though.