The Class Diagram that is used as as a layout template can have a specific diagram aspect defined. In other words, the layout template can only be used in another diagram with the same aspect. In the example below, the Control System Block Definition Diagram is a layout template with the electrical aspect defined, so the Control System layout template can only be used in the electrical view of the system. In this case, the Control System layout template is used in the Climate Hardware Internal Block Diagram that is defined as electrical. This layout template can't be applied in the diagram with a different aspect defined, e.g., Communication.
Usage of a layout template with aspect. The illustration displays concepts from SysML Plugin.
The sample model used in the figure of this page is Diagram Aspects which you can find in modeling tool <modeling tool installation directory>\samples\SysML\diagram aspects.mdzip.