1. An image processing device comprising: a processor; and a memory which stores a plurality of instructions, which when executed by the processor, cause the processor to execute: obtaining an actual image including a motion part and a target object of an operation; recognizing the motion part from the actual image; defining an operation area of the actual image based on a position of the motion part; computing a first image feature of the operation area; and generating a display image by setting, based on the first image feature, the operation area and/or the motion part to be a second image feature which differs from the first image feature.