God: To Be Heard and Not Seen?

I'm reading Al Mohler's He is Not Silent as part of my personal growth goals. Trying to strengthen my communication gift. He makes a statement that sparked a lot of scribbling in the margins of my book. Here is what he said, without giving much Biblical support for it:

Movies move us by the skillful manipulation of emotion, driven by sound track and manipulated by skillful directing techniques. This is exactly where the preacher must not go. The power of the Word of God, spoke through the human voice, is seen in the Bible's unique power to penetrate all dimensions of the human personality. As God made clear, even in the Ten Commandments, He has chosen to be heard and not seen. The use of visual technologies threatens to confused this basic fact of Biblical faith.

Now, before I go on my tirade about this...because I truly respect Dr. Mohler and acknowledge that his spiritual understanding and maturity far exceeds my own, can someone help me get this from a Biblical perspective? I see God communicating through visual means over and over in Scripture- the Tabernacle, the Passover Seder, the cloud by day and fire by night, the ripping of the veil in the Temple, the Revelation to John. Even the Incarnation itself demonstrates God meeting our need to see him. I mean, I know the Incarnation is about much more than that, but I believe God appearing in human form was partially about letting us see Him (John 1:14, John 9:37, John 14:9). And Scripture talks so much about the Body of Christ and community of believers and that being a way for us to share our faith (John 13:35, John 17)-- that evangelism is not just about the words we say but the pictures of Christ that we show.

So yeah-- anybody out there who agrees with Dr. Mohler on this and can help me understand better?