There's a great class at my church that teaches different methods of prayer, and a few weeks ago we did visual prayer. It's something like what the article describes, but more involved. For homework we were supposed to practice visual prayer twenty minutes a day for a week.
I didn't expect to get anything from the exercise. I'd never done anything like it before, and praying by staring at a picture sounded unnatural and awkward to me. Maybe if I'd been raised Catholic... But I gave it a try with various images and found it very effective!
Then that very week I happened to run across the story linked above, so I tried the same exercise with Rublev's icon. At first it just looks like three angels sitting there, but focusing on the faces I saw the amazing love of the Father, and the listening obedience of the Son, and the loving submission of the Holy Spirit (qui ex Patre Filioque procedit, whatever the Russian Orthodox Rublev might have thought-- ha ha, I'm such a nerd). Then I started to envision my own relation to the three divine Persons-- I don't see how you could not be on your knees at that point.
The house behind the Father is supposed to evoke Jesus' words: "In my Father's house are many rooms.... I go there to prepare a place for you." To my own surprise, as I gazed at that worn and faded outline of a very simple house, it seemed to represent unimaginable peace. I had a great longing to go and dwell there forever.
Here's what the prayer class had us doing (sounds a bit awkward because it's been hastily translated from Spanish):
One takes an expressive picture, for example an image of Jesus, or Mary, or any other subject, a picture that makes a strong impression, such as peace, gentleness, strength. What is important is that it speaks to you deeply.
Take the picture in your hands and after calming down and invoking the Holy Spirit, stay quiet, simply looking at the picture, first as a whole, then in detail.
Secondly, capture intuitively, attentively, and with serenity the impressions this picture evokes in you. What does this image tell you?
Thirdly, with calmness transfer yourself to the picture, as if you were this image, or as if you were in it. Respectfully and calmly, make 'yours' the impressions this picture arouses in you. Thus, identify yourself mentally with this image. Remain so for a good while, and saturate your soul with the sentiments of Jesus which the picture illustrates. This is how the soul puts on the image of Jesus and shares in his interior disposition.
Finally, with this inner disposition, transfer yourself mentally to your daily life. Imagine difficult situations, and overcome them with Jesus' attitudes. This is the way to embody the image of Jesus in the world.
This exercise is particularly fruitful for those who are naturally imaginative.
I would just add that I am not naturally imaginative-- I'm very deficient in that area-- and I found the exercise "particularly fruitful" for precisely that reason. I've often tried contemplating scenes from the Bible, but while others report all sorts of images and insights after such exercises, for me it was usually an hour of frustration and boredom. Having an actual picture to look at made all the difference to me.