Transition won't animate

Question

I have a RelativeLayout with an ImageView centered:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/splashActivity_root"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.yarkoni.anybody.activities.SplashScreenActivity">

    <ImageView
        android:id="@+id/splashActivity_logo"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:layout_gravity="top"
        android:layout_margin="@dimen/spacing_medium"
        android:layout_centerInParent="true"
        android:background="@color/colorAccent" />

</RelativeLayout>

I am trying to animate the view to bottom:

TransitionManager.beginDelayedTransition(mRoot, new ChangeBounds().addTarget(mLogoIV).setStartDelay(1000).setInterpolator(new AccelerateDecelerateInterpolator()).setDuration(5000));
RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) mLogoIV.getLayoutParams();
params.removeRule(RelativeLayout.CENTER_IN_PARENT);
params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
mLogoIV.setLayoutParams(params);

Without the transition layout looks like this:

With the transition the layout looks like this:

The problem is that the animation doesn't actually occur instead the ImageView just appears on the bottom instantly.

EDIT 1:

The following fixes the problem:

mRoot.post(new Runnable() {
    @Override
    public void run() {

        TransitionManager.beginDelayedTransition(mRoot, new ChangeBounds().addTarget(mLogoIV).setStartDelay(1000).setInterpolator(new AccelerateDecelerateInterpolator()).setDuration(5000));
        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) mLogoIV.getLayoutParams();
        params.removeRule(RelativeLayout.CENTER_IN_PARENT);
        params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
        params.addRule(RelativeLayout.CENTER_HORIZONTAL);
        mLogoIV.setLayoutParams(params);

    }
});

But now my question is why when using handler it still does not work:

new Handler().post(new Runnable() {
    @Override
    public void run() {

        TransitionManager.beginDelayedTransition(mRoot, new ChangeBounds().addTarget(mLogoIV).setStartDelay(1000).setInterpolator(new AccelerateDecelerateInterpolator()).setDuration(5000));
        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) mLogoIV.getLayoutParams();
        params.removeRule(RelativeLayout.CENTER_IN_PARENT);
        params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
        params.addRule(RelativeLayout.CENTER_HORIZONTAL);
        mLogoIV.setLayoutParams(params);

    }
});