The avatar of Speedy was placed inside the substitute item, and Witch Sharon was very clear about it.
She wasn't a fool, nor did she have memory issues; she hadn't noticed the dissipating Speedy avatar simply because her attention wasn't on these details.
As long as she diverted a bit of her focus to observe her surroundings, she would naturally discover that the wisps of breeze escaping from the substitute item had all disappeared.
So, Dox's performance was to capture Witch Sharon's attention, blurring the true focus.
Only by making Witch Sharon lock her gaze on him could the "irrelevant details" be temporarily set aside. It was only under these conditions that Dox could continue to deceive Witch Sharon into using the Substitute Technique.
But even so, getting Witch Sharon to continuously focus on him wasn't an easy task.
Dox estimated himself that, at most, there would be one or two more chances before Witch Sharon would realize the Speedy avatar had vanished.
