別のライブラリフォルダに画像を移動したいのですが方法がわかりません。

Apologies on the delayed reply. Yes, click on the etc library to view all of its contents. Click on the asset you want to move, if you hover your mouse over its thumbnail you will see the heart icon. Click on the heart and you will see in the upper right corner of your screen a pop-up message with a Manage link. Click Manage to choose the hair library. This will move the asset to "hair". The file will no longer appear in "etc".