This is a common question asked on the game's Discord server. There are a few cutscenes you can enable that kind of show the player's body shape, but they are noncanon. It is my understanding that currently, there is no canon MC picture, because the lead creator, Hyao, wants people to imagine the main character to look like whatever they want, since there is character creation and customization in the game.
Having character models for several body type, in both male and female, as of now, seems unplanned. The devs are currently focused on more written content with the art as "extra". The visuals are not the main point of the game.