>>716064134
Kids have different proportions, and their heads are bigger. A ten year old would be like 5 heads high while an adult would be like 7.5 heads tall. Anime in general has girls drawn with bigger heads by default because subconsciously it makes them look younger. Loli type characters have even bigger heads than the standard. Pic related, these girls are twins but the one on the right got age regressed from 18 to about 6. Notice how the head size and shape are clearly bigger?