This works because block devices like /dev/sdX are just files. If you cp a file onto another file, it overwrites the data of the destination with the source. A block device represents the device itself, not the filesystem; if you wanted to put the ISO inside the filesystem, you’d have to mount it first.
Woah…
Damn I’m sorry for questioning this method, I didn’t know.
This works because block devices like
/dev/sdXare just files. If youcpa file onto another file, it overwrites the data of the destination with the source. A block device represents the device itself, not the filesystem; if you wanted to put the ISO inside the filesystem, you’d have to mount it first.