Tilly has a nose for wine and only drinks the best Chardonnay. Offer her an inferior Sauvignon Blanc and she'll turn up her nose. She'll still drink it of course, she'll just do it with her nose in the air.
Most Purrmaids think Lilly's a social drinker who does not really like wine. Judging by her constant expression that would be a reasonable, but wrong, conclusion. Lilly loves all wine, even the cheap stuff.