Bagliori are brilliant flashes of light, gleams, or glimmers. It's a beautiful and highly poetic word that you won't encounter in everyday conversation.
In the song, Annalisa sings, "Sono bagliori / Non è oro" (They are flashes / It's not gold). She uses this word to describe fleeting moments of hope that shine brightly but lack real substance, perfectly capturing the deceptive, on-and-off nature of a difficult relationship.
Annalisa's "Sinceramente" is a huge pop song with a surprisingly dark and complicated heart. She sings about a love that feels like being "sotto un treno" [under a train] and leaves her so shaken it's "Come morire, ma non capita" [Like dying, but it doesn't happen]. It's about that feeling of taking one step forward and one step back in a relationship, trembling and unable to sleep, but she's not just a victim here.
What's so cool about this song is how she owns her feelings. She asks her lover if they want the sincere truth or the poetic one, showing she's in control of the story. And even when she's crying, she says, "Non mi sogno di tagliarmi le vene" [I don't dream of slitting my veins]. It's a powerful way of saying that even in her deepest sadness, she's a survivor. She ends the song by repeating "Sinceramente tua" [Sincerely yours], which could be a declaration of love, or it could be her saying that all this pain and strength is the most honest version of herself.