Two Horse/Libra in one room is a 95–100% mirror, and the prettiest one in the zodiac. The DoubleSign canon literally calls Horse/Libra the most physically beautiful combination, so two of you together is, well, a lot to look at. Including for yourselves.
Chemistry is visual, sensual, and a little theatrical. Both Horse/Libra halves know exactly how to be admired and exactly how to admire back. The bedroom is choreographed because both of you cannot help yourselves. The risk: when the lights go up, you might be checking your reflection in each other's eyes more than checking on each other.
Conversation is graceful, witty, and frequently about the surface of things. Both Horse/Libra halves prize the polish. Real talks, the unflattering kind, the unphotogenic kind, have to be scheduled because neither of you naturally heads for them.
Friction lives in vanity. Two ambulatory Versailles in one foyer means competing mirrors, competing wardrobes, competing audiences. Cattiness, frippery, and shallowness are canon-listed Horse/Libra vices, and you have them in stereo. Petty arguments compound fast.
What each Horse/Libra needs from the other is the canon's own prescription: substance behind the facade. The body is already perfect. Concentrate on the mind for a while. Read together, learn together, become deep together, and your shared beauty stops being the only thing holding the relationship up.
At 95–100%, this is a stunning match on every visible metric. Two Horse/Libra will photograph well at every event. Whether the photos still mean something in twenty years depends on what you build behind them.