Chinese smartphone makers are co-branding their flagship devices with design houses such as Porsche Design or Lamborghini to compensate for low reputation of their own brands

Of course, BlackBerry did this much before [and BlackBerry already was and remains a high-reputation brand].

OPPO wants to sell high-priced and high-specifications phones [because that's where the margins are], but a rich man doesn't want to carry a device branded OPPO. Unless this OPPO also has the Lamborghini branding, to compensate for the "cheap" OPPO branding. Ditto with Huawei trying to sell high-priced flagship devices to the wealthy guys using Porsche Design branding.