Prototype: Overlay menu should not appear on loading

Hello, as a designer who sends prototypes to his clients, the first 2-3 seconds of looking at the design are very important.
Right now - in the first 2 seconds there is an overlay menu that hides 80px from the design for 2 seconds. It causes many times for the logo and main menu to be hidden for 2 seconds and changes the whole experience of viewing the page.

Why not putting this menu on the bottom part of the screen. Invision did it great.