You put the `onContentChanged` once for single append action, I'm not sure if it works for all the cases when you append multiple items here. The only question is you only check the last item for multiple items case, and I'm not sure we can assume all the items would be the same type, especially gallery app might have image/video(but it seems filter out the video when in pick activity). Image/video mixed items with video at the end of array will be failed to resize previous images.