1. A display control device comprising: a detection unit configured to detect change of a screen; and a display control unit configured to execute, depending on change of the screen detected by the detection unit, any one or both of provisional update processing that generates predetermined matching result information based on a result of calculation on a previous frame displayed on the screen, searches the screen for a region similar to a specified image template by using the predetermined matching result information as part of a matching condition for a next frame, and performs overlay display of an icon in the similar region, and definitive update processing that searches for a region similar to the image template by using a matching condition larger than the predetermined matching result information, and performs overlay display of an icon at a position corresponding to the similar region.