The canopy is beautifully painted, with the dove of the Holy Spirit in the center. Unfortunately, my hand wasn't steady enough when I took a detail shot.
What was this curious arrangement for? Simple. The canopy served to amplify the priest's voice. Anyone who did public speaking in the days before sound systems trained his voice to project. It's a simple matter of frequent exercises and the average priest of those days didn't need no stinkin' sound system. Nonetheless, every little bit helps and a canopy, like this, was very effective. Some of the aging relics of the "spirit of Vatican II" will complain about ambos being raised to elevate the priest above the people. Damn right, they were. That was the best way for the people to hear what the priest was saying in his homily and people then were better at listening.