A lamp for a vehicle, comprising: an optical output unit including at least one surface light source, each surface light source including an OLED (Organic Light Emitting Diode); and at least one processor configured to: determine a partitioning of a light emitting area of the optical output unit into a plurality of light emitting areas; control each of the plurality of light emitting areas individually; control a sequential turn-on operation that turns on each of the plurality of light emitting areas in a first sequential order in a first color with directionality; and control a sequential turn-off operation that turns off each of the plurality of light emitting areas in a second sequential order with directionality, wherein the at least one processor is further configured to: based on each of the plurality of light emitting areas being sequentially turned on in the first color, control a size of the plurality of light emitting areas to be different during the sequential turn-on operation, characterized in that based on each of the plurality of light emitting areas being sequentially turned on in the first color, control a size of the plurality of light emitting areas to be gradually smaller during the sequential turn-on operation. an optical output unit including at least one surface light source, each surface light source including an OLED (Organic Light Emitting Diode); and at least one processor configured to: determine a partitioning of a light emitting area of the optical output unit into a plurality of light emitting areas; control each of the plurality of light emitting areas individually; control a sequential turn-on operation that turns on each of the plurality of light emitting areas in a first sequential order in a first color with directionality; and control a sequential turn-off operation that turns off each of the plurality of light emitting areas in a second sequential order with directionality, wherein the at least one processor is further configured to: based on each of the plurality of light emitting areas being sequentially turned on in the first color, control a size of the plurality of light emitting areas to be different during the sequential turn-on operation, characterized in that based on each of the plurality of light emitting areas being sequentially turned on in the first color, control a size of the plurality of light emitting areas to be gradually smaller during the sequential turn-on operation. determine a partitioning of a light emitting area of the optical output unit into a plurality of light emitting areas; control each of the plurality of light emitting areas individually; control a sequential turn-on operation that turns on each of the plurality of light emitting areas in a first sequential order in a first color with directionality; and control a sequential turn-off operation that turns off each of the plurality of light emitting areas in a second sequential order with directionality, wherein the at least one processor is further configured to: based on each of the plurality of light emitting areas being sequentially turned on in the first color, control a size of the plurality of light emitting areas to be different during the sequential turn-on operation, characterized in that based on each of the plurality of light emitting areas being sequentially turned on in the first color, control a size of the plurality of light emitting areas to be gradually smaller during the sequential turn-on operation. based on each of the plurality of light emitting areas being sequentially turned on in the first color, control a size of the plurality of light emitting areas to be different during the sequential turn-on operation, characterized in that based on each of the plurality of light emitting areas being sequentially turned on in the first color, control a size of the plurality of light emitting areas to be gradually smaller during the sequential turn-on operation.