使用Batch打开文件夹中的随机文件

I'm an artist who is learning programming and I wanted to create a batch file that will select a random picture file from my references folder. The goal being to get a random picture to work on and study. I've looked around and the replies I see are hard to understand and are often linked with other features and functions I don't need. Simply put, how do I make a batch file that opens a random picture file from a folder (and subfolders)? Do I need to index every picture and then have a selector from that or can I just use %random% to open it?I'm an artist who is learning programming and I