Overfitting and pretrained models

Looking for some knowledge from a more experienced person.

I have trained two models on the “torch.hub.load” alexnet, one with pretrained=True and one with pretrained=False.

I have then applied the Grad-Cam method on the results. My interpretation is that the pretrained=True is not overfitted, it identifies the object and provide nice shapes. While the pretrained=False identifies the object, but Iooking at the gradients indicate overfitting, since it is just a splash of tiny pixels within the area of the object. No real shapes can be seen here.

Am I correct, or is there a better opinion here? (Thank you for your time.)

Pretrained = True:

Pretrained = False: