The answer is: An interest in the Chinese online market.
In June 2016 Walmart acquired a 5.9% stake in JD.com, the Chinese ecommerce marketplace listed on Nasdaq since 2014. In January 2017 Walmart had upped its stake in JD.com to 12.1%.
In October 2016 Asda (owned by Walmart) and JD.com announced a collaboration to bring 'British authentic merchandise' to the Chinese market.
In June 2017 JD.com acquired a minority stake in Farfetch with the two companies announcing a collaboration in the Chinese market, bringing authentic luxury goods to Chinese customers.
What do luxury brands really think of Farfetch's business model?
How is the Walmart relation perceived among luxury brands?
Will Farfetch's 'supplier stores' have to pay a higher commission to sell to China using the JD.com network?
Gossip from within any of the companies mentioned much appreciated. Feel free to comment. Note that we moderate responses.