How to preload widgets on flutter web

Question

I am new on flutter and I am building a little website with it to learn. You can check it here: https://nagolove-d8d94.firebaseapp.com

It works only on mobile now. So the question is - when I switch on appbar to second section there is little img preload time, that looks not good for me. Is there any way to preload sections before they were displayed?

I use this to switch with animation:

final List<Widget> _screens = [
const MainBlock(),
const SalesBlock(),
Container(color: Colors.blue),
const ContactsBlock(),];


body: RepaintBoundary(
  child: AnimatedSwitcher(
   duration: const Duration(milliseconds: 250),
   child: _myAnimatedWidget,
  ),
),

Thank you for help in advance