It’s not an ISO. I actually hadn’t realized that so many people were used to ISOs of Despecialized rather than folders, and that there was a bit of a gap in knowledge as far as people knowing the relationship between these two things.

Do you have VLC or a similar media player installed? If so, you can open those folders and in the stream folder, there is an m2ts file that opens in VLC (this is what plays when you have the iso mounted). Right clicking the BDMV folder also gives an option to Play in VLC, I think.