Why can't I move all images to SD card? I wanna move ALL my photos, videos, music, etc. to the SD card, so I can give my phone to a friend.

This is the space used by all that stuff and what I see when I click "Transfer data to SD card":

 

Only 1 file! (The previous screenshot.) So, why can't it see the half Gigabyte of "Pictures, videos" from the first image, as well as the Downloads, Misc...?

EDIT

I'm using Android 4.4.2 on a Sony Xperia D2104.
This would have to do with the manufacturer's implementation of the "file manager" you are using and where it is allowed to move files from and to, most likely out of your control but you did not mention what device or android version or any other information of use to assist in that capacity.

I would suggest connecting the phone to a computer and transferring the files that way, or using a different file manager such as one of the applications in this article which allows relatively full control over the file system and SD card.