A method performed at a server machine comprising: receiving a user submission that includes a conditional modification program, a trigger condition for execution of the conditional modification program, and a corresponding value accorded to the conditional modification program; and based on the value accorded to the conditional modification program, determining a period of time during which the conditional modification program is to be specified by object data that defines an augmented reality, AR, object; providing , to a user device and by one or more processors of the machine, the object data that defines the AR object, the object data of the AR object specifying a physical geolocation of the AR object, a presentation attribute of the AR object, the conditional modification program of the AR object, and the trigger condition for execution of the conditional modification program, the provided object data causing the user device to present the AR object with a first appearance and located at the physical geolocation; detecting (420; 920), within the determined period of time and by one or more processors of the machine, fulfillment of the trigger condition specified by the object data for execution of the conditional modification program of the AR object; based on the detected fulfillment of the trigger condition and by one or more processors of the machine, executing the conditional modification program of the AR object, the executing of the conditional modification program modifying the object data of the AR object by modifying the presentation attribute of the AR object; and providing , to the user device and by one or more processors of the machine, the modified object data of the AR object, the modified object data causing the user device to present the AR object with a second appearance based on the modified presentation attribute of the AR object. receiving a user submission that includes a conditional modification program, a trigger condition for execution of the conditional modification program, and a corresponding value accorded to the conditional modification program; and based on the value accorded to the conditional modification program, determining a period of time during which the conditional modification program is to be specified by object data that defines an augmented reality, AR, object; providing , to a user device and by one or more processors of the machine, the object data that defines the AR object, the object data of the AR object specifying a physical geolocation of the AR object, a presentation attribute of the AR object, the conditional modification program of the AR object, and the trigger condition for execution of the conditional modification program, the provided object data causing the user device to present the AR object with a first appearance and located at the physical geolocation; detecting (420; 920), within the determined period of time and by one or more processors of the machine, fulfillment of the trigger condition specified by the object data for execution of the conditional modification program of the AR object; based on the detected fulfillment of the trigger condition and by one or more processors of the machine, executing the conditional modification program of the AR object, the executing of the conditional modification program modifying the object data of the AR object by modifying the presentation attribute of the AR object; and providing , to the user device and by one or more processors of the machine, the modified object data of the AR object, the modified object data causing the user device to present the AR object with a second appearance based on the modified presentation attribute of the AR object. <EOS>