Could be both. Most chickens start with small eggs, some stay that way for quite a long time slowly getting bigger. Others start laying bigger fairly quickly. ASSUMING I've not missed Aurora's (Austra White) initial eggs since the first I knew about was in the alpacas' wall feeder, her first 2 were 54g and the one she laid today was 60g, well in the center of USDA Large. On the other hand Sophia (Columbian Wyandotte) has been laying for a couple of weeks and they are still 44 grams.

They must have been laying at the same time today because there was an egg at each end of the 4' box. Usually all the eggs are on the left side.