When pullets first start laying it's not unusual for them to lay these little eggs at first as the egg-laying "machinery" starts getting fired up. Takes practice! The eggs will get larger over time. These beginner eggs are sometimes called fairy eggs, rooster eggs, wind eggs or fart eggs. Also, sometimes the hen does not really know what is happening but with practice she will learn to lay in the nest. It helps to put golf balls or fake eggs in the nest. When she sees those in the nest it helps her know to put her eggs there too.
My Aussies have not started laying yet so I don't know if their eggs will be speckled or not, and I know nothing of ISAs. It is after midnight here (USA) so maybe we can get some answers in the morning!