If you (a) begin a set that contains the 'video' task and (b) don't complete that set and (c) do complete tasks that follow the video task then when you come back to complete the set you will start at the video task, rather than after the last task you finished.
The reason for this is that we consider you to have finished a task if you have generated at least one relevant result in it. The video task does not mark any of its results relevant, therefore you never appear to have finished it and it is assigned to you as the first uncompleted task in the set.
If you (a) begin a set that contains the 'video' task and (b) don't complete that set and (c) do complete tasks that follow the video task then when you come back to complete the set you will start at the video task, rather than after the last task you finished.
The reason for this is that we consider you to have finished a task if you have generated at least one relevant result in it. The video task does not mark any of its results relevant, therefore you never appear to have finished it and it is assigned to you as the first uncompleted task in the set.