Actually? She likes that flower better than others that could be deemed more "attractive" such as roses. Roses are overrated. Everybody gives roses to the girls they fancy.

And for this small act of giving her a dandelion (though something tells her that this wasn't the flower he intended to get at first), she likes him even more now. It's quite a touch of originality, and the flower is pretty in her opinion.

When she takes the flower, her fingers brush against his so very slightly for a moment.

"Merci, Monsieur" she smiles at him "You have quite brightened my day, with your flower and your beautiful exaggerations. It would have been boring had I not met you."