My latest shopping nightmare has been trying to find 12x12" or 4x4" photo frames that are already backlit or that I can easily backlight so I can put etched mirrors (or etched acrylic or glass) and have it look SUPER COOL. I feel sure that these things exist somewhere but trying to search the current web marketplaces (amazon, ali*, etc) is super frustrating.
For the backlit mirrors I just use shadow box frames from Michaels or Hobby lobby, then throw my own RGB led strips behind the glass. When those big box stores have sales you can get the frames cheap. Honestly the most expensive part was the led strips, and you can find them on Alibaba pretty cheap.
The 12"x12" frames perfectly fit the 12"x12" mirrors I get on amazon