If some giant towering over me would sudddenly get right in my face not respecting my personal space talking in a cutesy voice I would hate it too. Maybe the giant has bad breath and/or is asking me inappropiate questions like if I have a girlfriend yet or to come and hug him. I would be terrified.
Getting down to eye level to talk to small children is the norm in early childhood education. While getting my Montessori training, we had a special portion of the program learning how to appropiately adress children in a respectful way to invite them and engage in x or y activity. Even where we had to sit to teach a lesson depending if the child is left or right handed. Small details are very very important.
Lol yes to the “very serious conversation” bit, my kid would geta stern look at times and I always thought it was because for them, I was on “teacher” mode, very serious.