1. An image processing device comprising: one or more processors; and a memory storing computer readable instructions, wherein the computer readable instructions, when executed by the one or more processors, cause the image processing device to: acquire original image data indicating an original image, the original image including M lines of letter strings (the M being an integer of 1 or more) configured of a plurality of letters; and generate processed image data indicating a processed image by executing image processing on the original image data, the processed image having the plurality of letters expressed in an enlarged manner as compared to the original image, the image processing includes: judging whether to execute a first type of enlarging process or execute a second type of enlarging process based on the M lines of letter strings in the original image; in a case of judging to execute the first type of enlarging process, executing the first type of enlarging process on the original image data to generate a first type of processed image data indicating a first type of processed image including the M lines of enlarged letter strings configured of the plurality of letters enlarged, the first type of enlarging process comprising: a process to dispose the plurality of letters in the first type of processed image equal to a layout of the plurality of letters in the original image; and a process to enlarge the plurality of letters of the original image; and in a case of judging to execute the second type of enlarging process, executing the second type of enlarging process on the original image data to generate a second type of processed image data indicating a second type of processed image including N lines of enlarged letter strings (N being an integer of 1 or more) configured of the plurality of letters enlarged, the second type of enlarging process comprising: a process to dispose the plurality of letters in the second type of processed image in a different layout from the layout of the plurality of letters in the original image; and a process to enlarge the plurality of letters of the original image.