Regarding placing a picture under the pillow by a bris:
After asking many people about it, here’s what I found.
Majority of people I asked hadn’t ever seen it, some had heard of it before, none knew the source, or if it was widely done.
A mashpia I asked told me that the Rebbe in fact addressed this Minhag, and said it originated after Chassidim wanted the Frierdiker Rebbe to be Sandek, but he couldn’t be present, so they placed a picture of him under the pillow. I looked for a source for this, and didn’t find any. (That doesn’t mean that there isn’t) The person who told this to me didn’t recall where he heard or saw it.
A prominent Lubavitcher Rov I asked had heard of it, but didn’t know if there was any source for it. He said that some people do it, and many others don’t. As for himself, he said he wasn’t makpid on placing a picture under the pillow.
Some people suggested that the reason why many have never seen it, was because the mohel places the picture there, and most people don’t notice it.
Regardless, I don’t know why anyone would consider it A”Z of any kind.