The story of the replica Tudor usually revolves around its sibling status to the replica Rolex, but since entering the UK market a couple of years ago, it's been strident about its role in both developing the iconic 'tool watch', and for supporting those adventurers, spiritual or otherwise, who've decided to wear its robust and lately highly collectible pieces. 
The choice of Lady Gaga, then, fits with a brand profile that's moving away from equipping explorers and other items, and joining a broader discussion around what does and doesn't fit the 'status quo.
With her six Grammys, Golden Globe, and 30m albums sold, Lady Gaga has clearly prospered in the mainstream whilst greatly abstaining from its cookie-cutter standards; ditto Tudor replica, which has helped bring fabric straps a lot recently and 'neo-vintage designs back to the horological fore. 
Now we have another question, why are some fake watches referred to as chronometers?
The term chronometer (which simply means "time measurer" in Latin) can only be used in the movement in question has been tested and certified by an independent authority. Although there are many of these bodies around the world, in practical terms this normally means the Swiss Official Chronometer Testing Institute. The institute tests the movements submitted to it for their accuracy over a period of 15 days: the first ten at room temperature and for the last five at a range of different temperatures. The measured timekeeping deviations must lie within pre-defined tolerances, usually, of -4/+6 seconds per day or a precision of 99.99%, the most accurate mechanical movement can be. If this is the case, then a Swiss Official Chronometer certificate will be issued for the movement and as such is a mark of quality. The term chronometer was originally coined by Yorkshire clockmaker Jeremy Thacker in the early 18th century in his unsuccessful quest to build a clock accurate enough for marine navigation - the problem being how to deny the effects of the motion of the ship. This was important for marine safety and exploration and so of vital concern to the British as the pre-eminent naval power of the age. Self-educated carpenter John Harrison then took up the challenge was ultimately and one of his chronometer designs was used by Captain Cook used his during his second and third voyages. Harrison made himself the equivalent of a multi-millionaire owing to his efforts - and helped the British Empire to dominate the world's oceans for the next century. 
And the results are even more outstanding than the fake Zenith's landmark achievement to a certain extent, the legendary El Primero from 1969, the first serially produced chronograph capable of measuring to 1/10th of a second, made possible by the higher oscillating frequency. Because today the fake Zenith has announced a new movement beating at an incredible 15hz or ten times more accurately than the original El Primero.
Featured inside an upgraded movement called the ZO 342 is an entirely new regulating system dubbed the fake Zenith Oscillator, which replaces the coupled balance and hairspring ("sprung balance") system devised by the astronomer and physicist Christiaan Huygens back in 1675 with a single element measuring just 0.5mm thick.
The Oscillator itself is made from monocrystalline silicon and its two components replace the 30 or so parts that comprise the traditional sprung balance system. The usage of monocrystalline silicon obviates the need for lubrication, resulting in less friction, which - in tandem with the increased frequency - achieves far greater accuracy for 95 percent of its 60-hour power reserve (which is ten percent greater than the original El Primero, despite the uplift in frequency).
This gives the Defy Lab a triple-whammy of credentials: chronometer certification awarded on behalf of the International Bureau of Weights and Measures (BIPM), as well as thermal and anti-magnetic properties that meet criteria laid down by the International Organization for Standards (ISO). As the replica Zenith describes it, "This mechanism opens up a new dimension, representing no less than a reinvention of the Huygens principle with another mechanical replica watch."
Initially offered in ten unique pieces (all of which are pre-sold), the fake Zenith Defy Lab features a 44mm case made from a patent-pending aluminum composite developed by the R&D team at Hublot, called Aerosmith, which is billed as 1.7 times lighter than aluminum and 10% lighter than carbon fiber. Finally, the aim is to industrialize the Zenith Oscillator as the El Primero, but until then there's the Defy El Primero 21, a chronograph capable of measuring to 100th of a second via a central seconds hand the first series-made chronograph able to do so, and the debut piece in this newly-minted line of Defy replica watches.