It should be possible to configure a Card to experiment with it

Note that for the thumbnail, to change the image requires first removing it entirely, the controls should include a note about that. (T312540)

For the thumbnail, it appears that the width/height properties aren't actually used at all, and so do not need to be configurable yet (and probably should not be available, to avoid confusion). (T312580)

The Card component assumes that the title slot is set, in that it is unconditionally rendered with a surrounding span. There is no way (yet) to make the controls enforce required slots like this, hopefully once T309905 is done such non-empty validation can be added.