1. A printing system comprising: a printer; and a terminal device configured to communicate with the printer, wherein the terminal device comprises: an interface configured to communicate with the printer; a display; a processor electronically coupled to the interface and the display; and a memory storing instructions that, when executed by the processor, cause the terminal device to: transmit print data to the printer, the print data including location data representing a particular location where image data representing an object is stored, the particular location being different from the printer and the terminal device; transmit a layout data request to the printer, the layout data request including a request for requesting the printer to transmit layout data to the terminal device; receive the layout data generated by the printer; and generate a preview image data based on the layout data, wherein the printer comprises: an interface configured to communicate with the terminal device; a processor electrically coupled to the interface; and a memory storing instructions that, when executed by the processor, cause the printer to: receive the print data from the terminal device; receive the layout data request from the terminal device; transmit, in response to receipt of the layout data request, an external data request to the particular location in accordance with the location data included in the print data; receive external data from the particular location in response to the external data request, the external data including size data representing a size of the object, the size data being included in a header of the image data; generate area specifying data specifying a particular area on a print sheet, wherein the area specifying data indicates that the object is arranged in the particular area in case that the object is printed on the print sheet, and wherein the area specifying data is generated based on the print data and the size data included in the external data; generate the layout data based on the received print data and the generated area specifying data; and transmit the generated layout data to the terminal device, wherein the instructions stored in the memory of the terminal device, when executed by the processor of the terminal device, further cause the terminal device to: generate the preview image data based on the layout data, the preview image data being generated by placing the image data in accordance with the area specifying data included in the layout data, the preview image data representing a preview image of the print data on the print sheet; and display the generated preview image on the display, wherein the print data includes vector data, wherein the layout data includes background information representing a background image of the preview image, and wherein the background image represented by the background information includes an image which is drawn based on the vector data.