Label variation. This is the first pressing (from after Liberty acquired Blue Note), which can be determined by the layout of the labels, which follows the original BN 'build up': top of label opens with the album title without quotation marks first, then follows with artist's name [see images]. Other examples of this layout/build up can be found here (Joe Henderson) and here (Andrew Hill). The labels of the 1st pressing still follow the 'look and feel' of original BN labels and carry the original 'Blue Note blue' on white, but with "Blue Note Records • A Division Of Liberty Records, Inc." as rim text.
The 2nd pressing uses a new, darker blue on white and changes the layout of text on the label, including the fonts, and opens with the artist's name first, then follows with the title between quotation marks [see and compare images].