A "light facelift" means making small changes or improvements to the appearance of something, typically without making any major or significant alterations. Full definition
A March 1985 light facelift brought a new asymmetrical grille (although not for the Cabriolet) and some interior improvements. (en.wikipedia.org)
I was so disappointed with the design of the first BMW Phantom and this is the lightest facelift (and not a good one to my eye) of an inelegant design. (evo.co.uk)
According to this pictures caught in South Korea, Hyundai will be preparing a light facelift to his full - size premium sedan, the Equus. (thekoreancarblog.com)