15. A system comprising: a memory; and at least one hardware processor coupled to the memory and comprising instructions that causes the system to perform operations comprising: receiving presentation data from a client device, the presentation data including a set of presentation elements; generating a composite presentation, based on the presentation data, and cause display of the composite presentation within a graphical user interface that comprises a first region and a second region on a group of devices, the first region of the graphical user interface comprising a display of the composite presentation that includes a first presentation element at a location among the arrangement of the set of presentation elements, and the second region of the graphical user interface comprising a newsfeed to display annotations on the composite presentation; receiving a selection of the first presentation element from a first device from the group of devices, the selection including a user input onto the composite presentation, and to request annotation data from the first device in response to the user input onto the composite presentation, the annotation data including an indication of an annotation type, and an identifier associated with the first device; and causing display of a notification element at the location corresponding to the first presentation element among the arrangement of the set of presentation elements within the composite presentation, the presentation of the notification element comprising a graphical icon selected based on the annotation type, and including an annotation identifier and the identifier associated with the first client device; updating the newsfeed within the second region of the graphical user interface to include a depiction of the annotation data that comprises the annotation identifier and the identifier associated with the first client device; receiving a selection of the notification element; and responsive to receiving the selection, presenting the annotation data associated with the notification element within the second region of the graphical user interface.
19. The system of claim 15 , wherein the notification element further comprises: a first portion including a presentation identifier of the composite presentation; and a second portion including a user identifier associated with the first user device.