.mkv (Matroska) and .mp4 are both video containers. A legitimate file would only use one.
At its surface, the title suggests a benign or therapeutic video—perhaps an ASMR clip involving the manipulation of fruits or a tutorial on natural skincare. However, the internet history of this specific file name suggests two primary identities:
The Anatomy of a Digital Mystery: Understanding "Fruit Massage.mkv.mp4"