What happens when you drop a dimension into a blank part of a report that contains two blocks, without the ALT key selected?

A new block is only created when the dimension is dropped while holding the ALT key, not by default.

When a dimension is dropped onto a blank area of a report without the ALT key held, Web Intelligence interprets the action as a request to create a section header based on that dimension. Holding ALT while dropping is the specific gesture required to create a new standalone block instead. This default behavior reflects the tool's design to promote sectioned report layouts.

Web Intelligence does not display an error for this action - it simply applies the default section-creation behavior.

Displaying the currently selected cell is not a behavior associated with drag-and-drop dimension placement in a blank report area.