Do you have any ideas for hiding a wall of mirrors in a rental?

It always helps to see photographs of any situation where advice is being asked. How much of the wall is covered? How high and how wide are the mirrors?

You can use fabric. There are

You tube videos available that show how to do it. Use corn starch or a commercial fabric starch liquid, not spray and use the fabric like wall paper. When you move, peel off the fabric and just wash the mirrors . The starch will just wash off. And I hated those mirrored walls in the 80s. Hope this helps!

What about removable contact paper

Peel & stick removable wallpaper

Stencils

Hang curtains so it looks like there is a window behind them.

I've never used removable wall paper and have heard mixed results. That would be my preference I think. Is it really removable? Is there a specific brand that works better than others?

I would hang a wall sized curtain over it. It will be pretty, soft and cover the mirror.

here are videos /ideas how to cover them up https://www.youtube.com/results?search_query=diy+starch+lace+window+film

I would also use a curtain or tapestry.