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Hi Laura,

Pasting images in AutoCAD for PC is possible because of Windows OS specific feature - OLE, which is not available in macOS.
So there is only one way to place raster images into drawings on Mac - attach them as reference with IMAGEATTACH command.
AutoCAD 2021 for Mac has new feature - display images imbedded into drawings in AutoCAD for Windows, but you still cannot imbed them on Mac. Plus there is limitation - you cannot see in AutoCAD 2021 for Mac images that were copy-pasted on Windows side, you can see them if they were activated as Bitmap Images after insertion.