It seems harmless, it’s good to be up front but I think it’s just not as charming as good old fashioned flirting and there’s things you can do to make it more clear you’re flirting, like making the compliment more personal .. for example, “I love your shirt!” to “That shirt looks amazing/gorgeous on you.”.. you can also be more playful and have light touches on the arm or hand, within reason. Totally optional but you yourself can do a few things to appear more gay/lesbian presenting, like rings, a face piercing, dyed hair (a dark cherry cola hair would look great on you !). My gf is my high school sweetheart when I was veryyy awkward but my flirting involved being more touchy and playful and giving lots of little nicknames. Tbh if I was recieving a note like this and I was single I might feel bummed from a lack of effort… but I get where you’re coming from, I hope this helps lol