Different edition or just inaccurate information?

[Jason]

I own a book which shares the ISBN numbers associated with this. My copy has a different cover and is what I would consider a mass market paperback. When I look up the book on Amazon I see the cover that is in the goodreads page on the edition (https://www.goodreads.com/book/show/7...) and the same ISBN, along with dimensions that are slightly larger than the dimensions of my book at home. Not sure what is to be done here; should it be considered a different edition even though the ISBN seems to be the same? An alternate cover?

[Scott]

I've never seen a Penguin classic that wasn't a trade paperback.