Being able to do this would be helpful. This may be a feature request or plugin idea.
You are able to automatically generate an index of a folder with Waypoint plugin, among others. However that would just be a list of links not embeds.
Manually, you could copy those automatically generated indexes and paste them into a new note. In the new note you could Search and Replace [[ with ![[.
I am interested if someone has a good solution or if you make a request. Good luck!
Thanks.