There is no way that rock has enough gravitational attraction to hold that smaller rock in orbit.
Did you do a calculation?
It’s estimated to be nearly one mile in diameter.
A minor-planet moon is an astronomical object that orbits a minor planet as its natural satellite.
As of June 2019, there are 357 minor planets known or suspected to have moons.[1]
Discoveries of minor-planet moons (and binary objects, in general) are important because the determination of their orbits provides estimates on the mass and density of the primary, allowing insights of their physical properties that is generally not otherwise possible.[2]
The first modern era mention of the possibility of an asteroid satellite was in connection with an occultation of the bright star Gamma Ceti by the asteroid 6 Hebe in 1977.
The observer, amateur astronomer Paul D. Maley, detected an unmistakable 0.5 second disappearance of this naked eye star from a site near Victoria, Texas.
Many hours later, several observations were reported in Mexico attributed to the occultation by 6 Hebe itself.
Although not confirmed, this documents the first formally documented case of a suspected companion of an asteroid.[3]
A minor planet is an astronomical object in direct orbit around the Sun (or more broadly, any star with a planetary system) that is neither a planet nor exclusively classified as a comet.[a]
Before 2006 the International Astronomical Union (IAU) officially used the term minor planet, but during that year’s meeting it reclassified minor planets and comets into dwarf planets and small Solar System bodies (SSSBs).[1]
Minor planets can be dwarf planets, asteroids, trojans, centaurs, Kuiper belt objects, and other trans-Neptunian objects.[2]
As of 2019, the orbits of 794,832 minor planets were archived at the Minor Planet Center, 541,128 of which had received permanent numbers (for the complete list, see index).[3]
The first minor planet to be discovered was Ceres in 1801.
The term minor planet has been used since the 19th century to describe these objects.[4]
The term planetoid has also been used, especially for larger (planetary) objects such as those the International Astronomical Union (IAU) has called dwarf planets since 2006.[5][6]
Historically, the terms asteroid, minor planet, and planetoid have been more or less synonymous.[5][7]
This terminology has become more complicated by the discovery of numerous minor planets beyond the orbit of Jupiter, especially trans-Neptunian objects that are generally not considered asteroids.[7]
A minor planet seen releasing gas may be dually classified as a comet.
Objects are called dwarf planets if their own gravity is sufficient to achieve hydrostatic equilibrium and form an ellipsoidal shape.
All other minor planets and comets are called small Solar System bodies.[1]
The IAU stated that the term minor planet may still be used, but the term small Solar System body will be preferred.[8]
However, for purposes of numbering and naming, the traditional distinction between minor planet and comet is still used.
https://en.wikipedia.org/wiki/Minor_planet#Provisional_designation
“There is no way that rock has enough gravitational attraction to hold that smaller rock in orbit.”
A little advice? Stick to simple things like talking to your pets.
Physical characteristics
1999 KW4 has a minor-planet moon orbiting it.
The moon, designated S/2001 (66391) 1 is approximately 360 metres [~.22 miles] in diameter, and orbits its primary in every 16 hours at a mean-distance of 2.6 kilometers [1.61 miles].
The presence of a companion was suggested by photometric observations made by Pravec and Šarounová and was confirmed by radar observations from Arecibo observations and announced on 23 May 2001
https://en.wikipedia.org/wiki/(66391)_1999_KW4#Physical_characteristics
I agree it does seem odd that it can hold a moon in orbit.
It depends upon the period of the rotation. I think the real period is about 17 hours. The speed in the video is exaggerated.
Gravity works at all scales. Absent significant external forces, that small rock will orbit the large rock forever. If they get very close to a massive object at the right time, there could be enough differential attraction to perturb the small rock's orbit. If that occurred frequently and in sync with the orbital period, the small rock could eventually be stripped away.