(Hint: press ctrl+a on a computer or long press on your phone to reveal the Dvar Torah)
וְעָשִׂיתָ בִגְדֵי קֹדֶשׁ לְאַהֲרֹן אָחִיךָ לְכָבוֹד וּלְתִפְאָרֶת
You shall make holy garments for your brother Aharon, for honor and glory
Aside from all the holy symbolism contained in the garments of the Kohen Gadol there was was another simpler reason for them, to give honor and glory to the position. He was going to be a leader and as such was required to dress for the part. As humans we often base our judgement on what we see, and since we are to follow his lead, he had to look honorable. The Gemara even tells us that if he wasn’t wealthy he would be given money so he would be so that no one felt any – even illegitimate – reason to look down on him.
A student of the Chafetz Chaim was telling of the crushing poverty they suffered from back then. Many students barely even had what to wear, and what they did have was tattered. The students stayed at Yeshiva for most of the year. Any time a student was going home though, the Chafetz Chaim would make sure to gift him with a new article of clothing. In yeshiva everyone understood what was going on, but the Chafetz Chaim wanted that when the Yeshiva students would go home, no one would use them as an excuse to look down on the Torah or those who study it.
We should be very careful ourselves not to chas veshalom disrepect the Torah or any representatives of Torah in any way.