Can video files created using the LEGO Movie Maker app be accessed directly?
While I wasn't able to find a way to export the videos via the application UI, I was able to locate these at the following path on Android: /data/data/com.lego.moviemaker.thelegomovie2/files

On my device, there were mp4 movie files located here along with a few other files. These can be moved around like any other file, and play just fine using VLC or other media players. You likely need a rooted device to access these.