The darker side of Lady Elaine can be problematic. She relishes mischief. She detests authority. In short, she can be a turd. She will often sets characters against each other just to see what will happen next and she loves scaring Daniel Tiger for pleasures' sake.
The Neighborhood is her cage: the inhabitants, her pets. When she noticed how pompous and narrow-minded King Friday was (the day she brought him home from her personal pet store), she assigned him the role of king - so she could gloat over what a stooge he makes of himself. She rounded up other pets that would obey Friday's every word. An owl, pussy-cat, platypus, a Cornflake Especially. If it starts to get a little dull in her cage, she stirs it up a bit and takes in the show gleefully. All the time, Lady Elaine dominates. Maybe that is why she was made with a permanent grin.