If you aren't looking for a DIY smart mirror, you might be referring to:
You can download the latest version from the MagicMirror² GitHub repository. Installation usually involves simple command-line prompts like: bash -c "$(curl -sL https://githubusercontent.com)" Use code with caution.
To build your own, you will typically need to download and install the software via a terminal on a Raspberry Pi.
You can download hundreds of third-party modules to display weather, news feeds, calendars, and even Spotify playback.