toddler sometimes refers to himself as a brother, like, "it's easy for a brother to do" (when cutting his own food) and, "it's not safe for a brother" (trying to get down from somewhere high up) and he sounds like a black guy from the seventies
put two crawling-age babies together for the first time and they'll often want to look at each other in the eyes, approach, touch each other's cheeks, mouth, eyes - usually, i have observed, parents try to prevent or greatly limit this interaction
put two toddlers together for the first time, with one or both of them holding a snack, and there will often be an interest in negotiating, often with little or no language, sharing or exchange of food - parents also often try to limit or prevent this
he does! i think he does this because when he's sweet or helpful to his baby brother i often say, "you're such a good brother!" so he knows "brother" is part of who he is