In thrilling greyscale.
The cover features Yusaki and one of his signature monsters, Decode Talker!
The attached card still remains unknown, the reveal likely reserved for V Jump
The Book is confirmed to explain about Link Monsters and the Extra Monster Zone and the generalized changes for New Master Rule (not Master Rule 4)
The Book also covers what to expect for the 2017 Rule Master Test.
Source: Weekly Shonen Jump