The phrase 「ああそっか なんだかこういうのって」 would need to be translated in conjunction with the hand-written 「てれっ = "I feel bashful/flattered/awkward"」, which is used almost like a sound effect or onomatopoeia here though it is originally the colloquial way of saying [照]{て}れる.
The little guy senses the satisfaction on the part of the big guy, which in return gives him a sense of achievement and positive awkwardness.
As in many other cases of J-to-E translations, one would have to use a few words that are not in the original for it to make sense in the target language. My own TL attempt might be something like:
"Never knew something like this would feel so awkward."