Sure thing! The important thing to remember about Event Sheets is that they're processed over and over, from top to bottom, in a never-ending loop (and dozens of loops per second).
In your screenshot, for example, if the user is holding "down", the event in the red box is triggered every tick. Meaning around 60 times per second, the "crouch" animation is being played - from the beginning of the animation, which is why you're seeing it stuck on the first frame.
In the screenshot below, you can see the "Duck" animation only starts playing if it's not playing already. So the user can hold the down key as long as they want, but the "Duck" animation will only play once, and play all the way through.
Let me know if this answers your question!