1. Thumbnail mode for vertical scroll bar
VS Code has this effect by default (at least I haven't set it specifically):

In fact, VS can also be set by clicking: Tools-> Options-> Text Editor-> All Languages-> scroll bar, and then checking "Use Thumbnail Mode (M) with Vertical Scroll Bar".

Let's see the effect:

2. Show and hide in-app toolbars
This item is about WPF. By default, the in-application toolbar will be displayed during debugging:

This can be turned off, but of course, we usually turn on it: Tools-"Options-" Debugging-"XAML Hot Overloads

You can dynamically switch:

Reference: