It's a very old question but I will answer this for future references.
To add any file to emulator just drag and drop the file.
The file will be copied to downloads folder of internal storage.
To access the file
Go to settings
Click On Storage & USB
Click On Internal Storage
Click On Explore (at the end)
and you got it in the downloads folder
now you will get notification to setup virtual SD card, follow the setup. after the successful setup you will be able to see pictures in gallery.
~ Answered on 2016-08-03 07:10:15