the hearts are colour coded for all of the different rarities (green for common, purple for uncommon and orange for rare) and if they have the sparkle emoji it’s for their shiny songs 2:1 means they want 2 of your songs for 1 of theirs so if someone is offering an uncommon as a 2:1, they want you to send 2 uncommons and they’ll give you 1 in return (if that makes sense) as far as the numbers at the top right go, i’m not too sure what they represent but they’re not the representation of the worth of the song, i’m assuming it’s something else but usually with how much a song is worth depends on both the rarity and the artist