The arms of the default skins are different compared to the java edition with different width ratios.

With the update on Alex and Steve's visuals I realized that... Before updating the visuals of Alex and Steve by default in the character creation part, the skins have two options for the arms, one being wider (with 4 pixels) and the other option being narrower/thinner (with 3 pixels).

After updating Alex and Steve's visuals along with the new characters, all Skins are coming by default with the wider arm option (with 4 pixels), but the before was with female skins with strict/thin arms and male skins with arms wider.

It is important to mention that I am also based on the Java edition version, as the female skins have thin arms (3 pixels) and the male skins have large arms (4 pixels).

 

Note: I don't know if it's a mistake, but the option with thin arms (3 pixels) is a little sloping on the shoulders compared to the option with wide arms (4 pixels). I put an arrow to better identify the location.