I thought Picture replaced the PictureFrame command.
If its supposed to be a replacement for BackgroundBitmap then why doesn’t Picture stay in the background? Making the Picture transparent is not a good substitute for having the image in the background.
A BackgroundBitmap exists in only one viewport. That’s a feature that allows you to set up different different views at different view angles. Suppose you have 2 views 30 degrees apart , With BackgroundBitmap you can setup 2 viewports each with its own BackgroundBitmap,
Both images can be visible in their own dedicated viewport at the same time but don’t interfere with viewing in any other viewport.
It obscures geometry also
BackgroundBitmaps are clearer than Picture images. There has been some improvement in this in Rhino6, but the images are still more blurry than the original. In V5 PictureFrame images were often so blurry they were not usable.