Whenever I’m critiquing myself the most common note I have is to slow down. What on stage feels like 5 seconds is probably closer to two on three seconds. Time seems to drag on when you are in front of a room full of people that are staring at you.
Over the summer I worked at a festival with another magician and each time he did a trick, he only displayed it for a second. Here’s an example, he did a Blendo type trick where multiple handkerchiefs turned into one. However once they became one he only showed it for about a second before he put it away.
The audience needs time to process what has just happened. By displaying for only a few seconds and then putting it away, they don’t get to appreciate what has just happened. You need to hold up the magic, and PAUSE, then put it way. That pause need to be long enough for someone to look at the final picture, then mentally compare it to the initial picture in their memory to understand the final result.
TLDR: Pause to show the effect