That is really interesting as have not found a post on that before.It was a gentle touch, just brushing his moustache and lips against my shoulder. I thought he might be asking for reassurance, so when he did it I spoke to him gently and stroked his neck. We walked for about half an hour like that, touch-stroke, touch-stroke. I've never had a horse do that before.
Ella does the same to me in her box. If I stand by her while she is eating her hay net. I am doing totally nothing. But she touches me. YO said she is lead mare. But then I read about herd behaviour in cows and cows touching each other. To confirm part of the herd. Unlike you, I dont stroke her back. She did the same with my grand daughter so it isnt personal affection for me. But a touch on every mouthful. The Rashid thing is that when I put the head collar on, it signified she is working for me. She doesnt do it with the collar on or when working and leading.