This is going to be brief since I am unfortunately not feeling well, but still wanted to write something.
The parsha's opening is strange -- why preface the details of how to make bigdei kehunah and the induction of the kohanim into their role with the command to make oil and light the menorah? What sense does it make to speak of "ya'aroch oso Aharon u'banav" at this point?
Rashi in last week's parsha asks why the command to place the luchos in the aron is given twice: once in 25:16 and again in 25:21.
ואל הארן תתן את העדות: לא ידעתי למה נכפל, שהרי כבר נאמר (פסוק טז) ונתת אל הארון את העדות. ויש לומר שבא
ללמד, שבעודו ארון לבדו בלא כפרת, יתן תחלה העדות לתוכו, ואחר כך יתן את הכפרת עליו
Rashi answers that the latter pasuk teaches that luchus should be put into the aron before placing the kapores on top (see Ramban there).
R' Shaul Yisraeli asks: what would be the hava amina otherwise? Once the kapores is on top, then how would you get the luchos in?
He answers that one might have thought that once you made a gold aron and a have a beautiful gold kapores to go on top, then what difference does it make if there are really luchos inside or not? So long as the externals are beautiful, who is going to know the difference?
Therefore, comes the Torah, as Rashi explains, and tells us that ruchniyus doesn't work that way. The superficial stuff, even if its all gold and looks beautiful, has no value unless there really are luchos inside.
Before our parsha gets into the beautiful garments that the kohanim wear, "l'kavod u'ltiferes," the parsha tells us that those beautiful clothes are no more than an adornment, but the real definition of kehunah is about what's on the inside, not what clothes are worn. The primary job of a kohen is to bring light to each and every Jew, as symbolized by the lighting of the menorah. That lesson has to come first, and only then can the Torah speak about the externals, the clothing.