Why images.unsqueeze(1) adds 2 dimentions

In:
img.shape

Out:
torch.Size([1, 28, 28])

In:
img = images.unsqueeze(1)

In:
img.shape

Out:
torch.Size([4, 1, 1, 28, 28])

Can anyone pls tell me why .unsqueeze fauntion adds 2 dimentions?
batch size = 4

Are you sure you are not mixing up img and images?
Additionally to the unsqueezed dimension img also has suddently a batch size of 4, which wasn’t there previously.
Could you print images.shape before unsqueezing it?