Discovered a possible "subliminal" image
I think I found a quasi-subliminal image that's been staring me in the face after multiple viewings - it's a "sort-of" Pazuzu-Howdy face that appears on the right side of Kinderman, behind his back, when he's interviewing Temple in Temple's office.
It's frequently shown on and around the 53:30 mark.
For anyone interested, I'd say it's Blatty's subtle way of revealing the demonic ambience of his story and a possible reference to the demon symbology of the Friedkin film - what do you think?