How to achieve CollapsingToolbar behavior like the plex android app?

Question

I did my best to educate myself on posting here, so let me know if I broke any rules that I can fix.

So here is the gif of the behavior I want to emulate:

But here is what I have:

Also I predict the layout will be important so I will post that too:

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:contentScrim="?attr/colorPrimary"
        app:layout_scrollFlags="scroll|exitUntilCollapsed">

        <ImageView
            android:id="@+id/detail_backdrop_imageview"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:scaleType="centerCrop"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            tools:src="@drawable/test_backdrop_w342" />

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />

    </android.support.design.widget.CollapsingToolbarLayout>

</android.support.design.widget.AppBarLayout>

<android.support.v4.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:behavior_overlapTop="32dp"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:paddingLeft="16dp">

        <ImageView
            android:id="@+id/detail_poster_imageview"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            tools:src="@drawable/test_poster_w92" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="100dp"
            android:text="TESTING" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="100dp"
            android:text="TESTING" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="100dp"
            android:text="TESTING" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="100dp"
            android:text="TESTING" />
    </LinearLayout>
</android.support.v4.widget.NestedScrollView>

I am beyond grateful if you have read this far. Again, please feel free to educate me if I made any posting errors, or let me know what I can do to make the question clearer.

Thank you!