Doesn’t seem like a depiction of Antarctica at all to me, but entirely of South American and the Caribbean.
Like nearly all early charts, the latitudinal accuracy is high, with distortion along the longitude. It’s still very interesting that there could have been explorations of the east coast of South America dating back before we ever thought possible, but it also reflects the basic “longitude problem” that plagued sailors for so many centuries before somebody came up with the answer: accurate timekeeping.
Given that sort of distortion, an early map could be stretched to resemble a number of coastlines. I’d like to see the comparison to the Antarctic coast.