Typically, when you get one more folder on the source drive than on the target drive, there was either a System Folder or Hidden Folder on the source drive that does not get copied. That doesn’t matter at all. Such a folder will be specific to the drive, or may have been created on the drive by some Windows process as it was the largest drive available, for example.
Often in these cases, even when you go looking for the “missing” folder you won’t find it, as you have your PC set to not display hidden and system folders.
As Mike says, the “Size on disk” doesn’t matter at all either. Unless the drives are formatted identically the Size on disk will always be different for exactly the same files stored on two separate disk drives. Again, that doesn’t matter at all.
What is most important is the the number of files matches, and the “Size” matches. In your case, the Size on the target drive is 3 bytes larger than the size on the source drive. That shouldn’t happen, but I see it occassionally, and have never had a problem with the copied files. If the Size was smaller on the target drive, I might be concerned and look into it. But when the Size on the target is larger by a very small amount, I think it is just a minor reporting difference between the two fomats on the source and target drives.
If you want, you could run CHKDSK on the target drive to see if it is okay. If it is, and you are still worried, you could run CHKDSK on the source drive and see if any errors are found. Also, the output of CHKDSK on each should confirm the size of the files on the drive.
But if all this sounds confusing then just accept that the copy shown in the image above for those two drives has worked fine.
