Complex sentence: Another reason for this is that on the album's artwork, the roman numeral for 6 (VI) is present.The roman numeral for 6 is present because the album was recorded in 2006 (In the year of VI).
Split into simpler sentences: Another reason for this is that on the album's artwork, the Roman numeral for 6 (VI) is present. The Roman numeral for 6 is present because the album was recorded in 2006 (In the year of VI).