In the Power BI Service, copying a matrix visual doesn't behave quite as expected, as follows:
1. Custom table accent colours are not picked up, being overriden with the defaults when copied.
2. When copying a matrix from Focus view, it only copies the image of the visual exactly as if it's displayed on the original layout. I've used Focus mode to make more data visisble and would expect it to copy that new focussed view, not the original view on the report page.
I haven't checked if these behaviours are true with other visuals, but hopefully this can be looked at, because otherwise, Copy visualas image is a great feature.