What's the difference as they contain the same files? - is the mnt a backup?

 

Can someone have a look using file manager or whatever, see if you have the same?

 

Found this too...

Nope...no backup. Should be the exact same directory. /sdcard is what you see from USB...basically the directory as it appears from the hardware. /mnt is where mounted volumes reside, so /mnt/sdcard is just the SD card as seen by the OS.