'While' also looking better the arms look a bit strange
The size of the hands was off compared to the rest of the arm, that's why. Generally, as the rule of thumb for drawing hands the distance between the wrist and the longest finger (middle finger) should be something like 7/8th of their head's height (from chin to top of the head), OR about 1/2 (for female) and 3/4th (for males) of your forearm.
Not to mention the upper arm lacks muscle tone/overall musculature compared to lower arm.