Asking to see other reviews
I'm writing this in my role as an editor: if I had assigned a younger colleague as a reviewer, and said colleague asked me for the other reviews because they want to learn what others see in a paper, I would usually be happy to forward them to her. Everyone wins if we help younger researchers find their bearings what is or is not expected in a review.

That said, there must be an understanding that the other reviews I forward will remain confidential and will not be distributed further. I imagine if you write to the editor who had assigned the paper to you, ask for the other reviews and explain why you'd like to see them, and promise confidentiality, then you may be able to get them.