@ptrblck: thank you so much for your input. Yes, it was a typo, corrected it now.
I completely understand what you are saying about the bottleneck - but, I was wondering about this below question (and hence chose 2):
[1] the siamese is almost a binary classifier with only two outputs (1/0 for same paid, different pair). The pretrained model is trained on a 1000 classes, but I have only 2.
Does this rational make any sense? In essense, the output from the pretrained model can at most have a 1000 classes (assuming 1000 classes is what the pt model is trained on?) If not, what should this number be? or is it another hyper paramter?