img = torch.arange(1 * 2 * 2 * 3).reshape(1, 2, 2, 3)   # N=1, H=2, W=2, C=3

print(img.permute(0, 3, 1, 2).shape)   # torch.Size([1, 3, 2, 2])  ✅
print(img.reshape(1, 3, 2, 2).shape)   # torch.Size([1, 3, 2, 2])  ⚠️ same shape!