Duplicade picture

@Vasilii

How to make 3 copies of the same image

You can 

1. Copy-paste (three times)
2. Select the image and duplicate it by
   1. selecting Duplicate from the context menu
   2. using the Ctrl/Cmd + D shortcut.
   3. using the Alt/Option + drag shortcut.
   4. using the Alt/Option + ←→↑↓ to duplicate the picture in a specific direction.

More on shortcuts & hotkeys here → https://help.miro.com/hc/en-us/articles/360017731033-Shortcuts-and-hotkeys

 if I replace one of images anothers two are replaced automatically

No. Each picture will be its own independent/unique object.

@Vasilii - Here is a Wish List post that you want to leave a comment on and upvote:

https://community.miro.com/ideas/share-or-embed-object-in-several-boards-5616