I feel like She was aged and get older in the years like she was 16 in 2007 and now in 2023 to 2024 she is now 32 years old
The Twitter post this picture was taken from has a comparison of two Mikus; her official art from 2007 and a piece of official(?) art from 2023, with a close-up on Miku's legs in each picture. They go from slender in 2007 to Ryza-esque in 2023.