Black tie doesn't mean you have to have a floor length gown, knee length cocktail dresses are also fine, as is midi length. You can also do looser trouser suits. It's about the vibe - it's elegance, it's gorgeous fabrics like silk.
When people argue with me about the length thing, my sources are a close family member who is high up in the armed forces and has attended many black tie events with another close family member who knows full well what the black tie rules for women are.
See also: Debretts, etiquette and dress code experts Events and Dress Codes • Debretts
All that aside, my personal opinion of the dress you've chosen is that it's really not for me. It's very expensive and for that price I'd want something more special. The drop waist would look aawwwwwful on me so maybe that makes the difference but I'm not a huge fan of the print. That's my taste though, not yours and if you love it, that's good enough. I feel like you asking about it here though suggests you're not altogether sure.