Things, in and of themselves, are not good or bad. It matters how they are used. When it came time to build the tabernacle in the wilderness, the Midrash tells us that the women came and said they wanted to have a share in it s building. We had jewelry but we already gave it away for the making of the golden calf. Moses was shocked at the idea.
Mirrors are the instruments of vanity.
It s out of the question. Accept them and use them for they are very precious in my sight. If it were not for those mirrors, there might not be a Jewish people. Because when the Israelites were slaves in Egypt, they had to do backbreaking work from morning to evening. They worked like animals, they were treated like beasts and when they came home at night they were exhausted.