AFIK, Mac can not browse android phones (Unless, the vendor adds support to it).
It should be able to receive files if the sharing is turned on. Check is receive files is set to allow.
Also try sending a different image to mp3 file.
Another problem is some times the bluetooth prompt. Check all open windows by press F3 or fn+f3 see if you missed the bluetooth prompt.
If you are using WIFI, I recommend you use AirDroid to transfer files between your android and PC