USB mass storage mode is no longer supported on latest Samsung Galaxy series including Samsung Galaxy Note II. What you have – Media device (MTP) and Camera (PTP) mode only. Luckily, there is a way to enable USB mass storage mode on Samsung Galaxy Note 2. Yes, it is working on Android 4.1 Jelly Bean firmware too. But have limitation which it is workable on external micro SD card only. It can’t mount internal sdcard as USB mass storage device. Furthermore, root access is required.
SGS3 Easy UMS is the free Android application that saves the day. Yes, it was developed for Samsung Galaxy S3 but still working on Galaxy Note 2 (since both of them are using the similar hardware).
Not yet root Samsung Galaxy Note 2? Please refer to this guide then ~ How to root Samsung Galaxy Note 2 with CF-Auto-Root? (Video).
Download SGS3 Easy UMS v1.7 here.