I think the my response to the "Is it too short?" question depends on when, where, and how you'd happily wear the dress. Objectively, the dress looks great, so no doubts there, and I'm all for baring knees regardless of age.
I have noticed that my own preferences have changed as I've grown older. Date nights, parties with friends, and summer festivals still have me happily reaching for my shorter skirts and dresses, but restaurants, galas, and the theatre, especially in the fall and winter months, are a different story. In those situations, I find myself craving a more sophisticated, adult look that is easier to pull off if my skirts are mid-knee or lower. Even when I'm wearing darker hose and boots, my shorter skirts just don't make me feel as good as do my longer ones when I'm in that mood.
If the dress is pricey, maybe think of when and where you might wear the dress before deciding. The dress looks lovely on you, and, objectively, the length is fine, but only you can judge the circumstances when you'd reach for that particular dress.