Если я понял ваш вопрос, самый простой способ - добавить imageView в макет CollapsingToolbarLayout, например:
<android.support.design.widget.CollapsingToolbarLayout
android:id="@+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:expandedTitleMarginEnd="64dp"
app:expandedTitleMarginStart="48dp"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<ImageView
android:id="@+id/iv_your_image"
android:layout_width="match_parent"
android:layout_height="280dp"
android:layout_marginTop="12dp"
android:paddingTop="48dp"
android:paddingBottom="48dp"
app:layout_collapseMode="none"
app:layout_constraintTop_toTopOf="parent"
/>
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar_fragment"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:adjustViewBounds="true"
android:background="@drawable/bg_main"
android:scaleType="centerCrop"
app:layout_collapseMode="pin"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light">
</android.support.v7.widget.Toolbar>
</android.support.design.widget.CollapsingToolbarLayout>
затем Glide.with(this).load(imageLink).into(iv_your_image)