Dataset export just the last labeled images

Hi, I just started to work with Roboflow for the design of an Object Detection dataset.
I suspect that my exported dataset has not incremental versions: images contained in the first exported version are not contained in the second version (developed labelling 100 more images).
I actually think that the second version is composed by the augmentation of just the last 100 labelled images.
Is this a desired behaviour?

I think you can access and look take a look at my incriminated dataset here.