Click "Create new album", select category, (optional) add title, select mirror current attachments if there are any. It can also be done after a thread has been made and will mirror all the attachments there too.
This works for things where you have picture contests, or events where pictures are going to be shared (concerts, birthdays, conventions), where you are expected to share picture of yourself or things (selfies, pets, cars).
🤷♂️ it's gotten more traction for the media gallery for me, and made my life easier after having commissioned it.