The change skin page on the profile settings for Java Edition uses the Steve and Alex skins to display the two different player models available, but the Classic model still uses the old Steve design rather than the updated 1.19.3 look. It is also in much worse quality than the Alex picture, being blurry and having a thin line between the legs which don't exist in the skin texture.
Last checked: October 21, 2023
The Steve image used to represent the classic variant of skins is now updated. Thanks for reporting.