Artificial means "artificial" or "fake". It's an interesting word because it immediately sets a tone of inauthenticity and deception within the song.
In the lyrics, the singer observes an "artificial rose" and connects its falseness to the person she's singing about, stating, "Parece real, mas a beleza que não passa / Assim como em você, é falsa" (It seems real, but the beauty that doesn't fade / Just like in you, is fake). This word is key to understanding the song's theme of superficial beauty masking a lack of genuine character.
This song is about being drawn to someone who is bad for you, and knowing it the whole time.
The singer looks at her partner and sees straight through the act. His charm is like an artificial rose: it looks real, but nothing about it is going to last. Even the things that used to make her laugh now just hurt her.
The chorus lays out the trap plainly: the kiss is good, but the person behind it is no good at all. And yet the more of a scoundrel he turns out to be, the more her heart leans in. She names it herself: the packaging is beautiful, but the content inside isn't worth much.