The first is a pretty straightforward version of the appearance of a conventional Madonna, a face surrounded by a wimple
The second is a bit more complicated, easily read as a wimpled head, but also suggesting the torso of a yakshini, in a "graceful, flexed pose known in Sanskrit as tribhanga, literally 'thrice-bent'."
The third, uncovered, suggests movement and seems to reference Marcel Duchamp's Nude Descending a Staircase (a different Madonna, perhaps) and his earlier experiments with depiction of movement.
And with the fourth (Our Lady of the Porcupine Quills) we are in new iconographic territory, with mantle in place but caught just after an unfortunate encounter: