What is your oshi's "The" stream? As in the defining, must watch stream that encapsulates what's special about her while establishing the tone of her streams from that point forward? The stream that you'd point someone towards if they wanted to start watching your oshi or even if they just wanted to get an impression of her?
It should be stand alone as well, short series are fine but no long term reoccurring content like AsaCoco or FWMC Morning (unless there's a specific stream you can point to).