I am going to use https://our.umbraco.com/Documentation/Reference/Angular/Services/eventsService/ I have a MediaPicker which I get it by its ID this way:

var x = umbRequestHelper.resourcePromise(
                                   http.get(umbRequestHelper.getApiUrl('mediaApiBaseUrl',
                                   'GetById',
                                    [{ id: 1331}]),
                                    { umbIgnoreErrors: true }
                                    ),
                                        'Failed to retrieve data for media id ' + imageUrl
                                ).then(function (data) {
                                    for (var d in data) {
                                        console.log(d +' = ' + data[d]);
                                    }
    });

I want to add an event listener to it so when its image changes I can notice. But I don't know what should I do exactly!

eventsService.emit("editorState.changed", { entity: entity });

what I should send to emit instead of "editorState.changed", { entity: entity } parameters? Is it the right way though?