Full disclosure: I took the quoted translation from elsewhere. I am not skilled enough to understand 8th-century poetry.
The poem describes a plum-blossom viewing party hosted by Ōtomo no Tabito, then Governor-General of Dazaifu, in the year 730 CE ("13th day in the first month of the second year of the Tempyō era"). Unfortunately this section isn't extensively analyzed (it will be though, now that they name Reiwa after it) so translations are spotty; not even the Nihon Gakujutsu Shinkō Kai (an otherwise comprehensive source, and one which IMHO provides the best translations for Man'yoshu poems) has a translation for it.
In any case, here's my stab at (some parts of) it:
"Wind is gentle" might be better than "soft". I also think "lovely" is more accurate for 淑く, but this I am less sure.
The plum blossoms line is a metaphor; basically linking the "pure" white of the blooming plum blossoms with the white (rice) powder used by women as make-up, applied while in front of a mirror.
The orchid line is another metaphor, this time linking the fragrance of the orchids with the hai or obidama, a jade (or milky stone like agate) ornament worn around the waist. The translator definitely dropped the ball with "sachet". I'm less sure about how the metaphor works here though (but "sachet" is definitely right out), but interpreting it as "(physically) after/behind the jade ornament" doesn't make sense, even if there was some unattested cultural practice to apply fragrances to the ornament. My theory is that 珮 is being used as a metaphor for (supreme) beauty, like it is in some ancient Chinese/Japanese poetry. So, "...fragrance given off after the most beautiful (of flowers blooms)" would be how I interpret it.
Thanks. I revised the translation to incorporate what you said, along with a little of my own interpretation.
It's pronounced "shoshun" there, though.
"Reiwa". 'Tis not bad. 'Tis written in the Man'yōshū, "In this auspicious month of early spring (初春), the weather is fine, the wind is gentle. The plum blossoms open, white as powder before a mirror; the orchids exhale fragrance from after supreme beauty blooms." Hm-hm-hm. Mine own name is within, is it not?