I don't understand how long it takes. It looks on the GIF like it's almost instant. Can you record a video and post it on Youtube instead? I may not have the answer, but I'm still a bit curious.
The top menu bar takes a while to load, that's the issue
Oh, thats because when you start up, no applications that offer menu bars are loaded. The menu bar shows up once finder finishes loading.
Just depends on how fast Finder loadsSometimes the menu bar loads instantly though