This TVC was aired long long time ago (many months ago), however their lakorn together had just been aired for a few weeks. At that time I also wondered why they would pair these two together in a TVC. Now that Miracle of Love is released, my curiously is resolved. Head&Shoulders is a shampoo and hair conditioner brand sold in Thailand and many other countries.
You should definitely check out this TVC because who knows when we would see Smart smiling and acting all cute like this again! Smart here is just totally different from the role of Khun Chai Burathad in Miracle of Love lakorn.