In Mavericks, any "diskutil mount" also mounts EFI volume

Question

Here's a diskutil command and output:
$ diskutil list disk1
/dev/disk1
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk1
   1:                        EFI EFI                     209.7 MB   disk1s1
   2:                  Apple_HFS Pocket                  724.2 GB   disk1s2
   3:                  Apple_HFS free2                   274.2 GB   disk1s3
   4:                 Apple_Boot Recovery HD             784.2 MB   disk1s4
So if I want to mount Pocket, I use "diskutil mount disk1s2"
Result:
Volume(s) mounted successfully
But now I also see a volume named "EFI" on my desktop. It wasn't there before. Apparently, "diskutil mount disk1s2" made it show up also. It doesn't show up along with Pocket and free2 when I connect the disk to the Mac.
Why does the volume named EFI (disk1s1) also appear on my desktop after using that terminal command?
Thanks.

Answer 1

Anyway, here's the AppleScript I wrote to toggle local volumes. It's similar to MERGING two Scripts to Unmount disks... but it's primarily an update for this item a Mac OS X Hints. The AppleScript attempts to unmount any currently mounted local volumes. If no volumes other than the boot volume are mounted when it runs, then all available volumes are mounted, and you're offered the option of re-mounting unmounted volumes if any volume can't be politely unmounted.
set alldisks to paragraphs of (do shell script ¬
                    "diskutil list|grep -v 'EFI EFI'|grep -v 'Recovery HD'|grep -o 'disk[0-9][a-z][0-9]*'")
          set all_non_boot_disks to paragraphs of (do shell script "df -hlg | awk -F/ '/disk*/ {print $5}'")
          set nonbootnumber to (count of alldisks)
          if (count of all_non_boot_disks) > 0 then
                    try
                              set all_non_boot_disks to items 2 thru nonbootnumber of alldisks
                    on error
                              set all_non_boot_disks to {}
                    end try
  activate
                    repeat with the_Item in alldisks
                              try
                                        set the_ID to (do shell script "df -hlg | grep -m 1" & space & ¬
                                                  quoted form of the_Item & space & "| grep -o 'disk[0-9][a-z][0-9]*'")
                                        do shell script "diskutil unmount" & space & the_ID
                              on error the error_message number the error_number
                                        if the error_message does not contain ":" then
                                        else
                                                  if button returned of (display dialog "A disk couldn't be unmounted.
                                        Would you like to re-mount those already unmounted?" buttons ¬
                                                            {"Cancel", "Re-mount"} default button 2) is "Re-mount" then
                                                            my mountAll(alldisks)
                                                  end if
                                        end if
                              end try
                    end repeat
          else
                    my mountAll(alldisks)
end if
on mountAll(alldisks)
          set actiondisks to {}
          repeat with i in alldisks
                    if i is not in actiondisks then
                              set actiondisks to actiondisks & i
                    end if
          end repeat
          repeat with myitem in actiondisks
                    try
                              do shell script "diskutil mount" & space & myitem
                    end try
          end repeat
end mountAll