Barrayaran culture is made up of many parts. On the one hand, they have a feudal political system that glorifies the military. On the other hand, they have absolutely gorgeous weddings. (Although these have moderated in recent years, the planet’s rabid anti-mutant biases mean that most Barrayarans refuse to acknowledge the existence of individuals who deviate from the standard “two hands” configuration.)
Anyway, GORGEOUS weddings. Very meaningful. Lots of groats. In the run-up to the wedding, we learn that Miles can effectively deploy his reputation as a murderer against people who believe, well, that he’s a murderer. He didn’t like those people anyway, so this is very convenient. The rest of Gregor’s wedding is also very educational.