When concentrating on individual parts of a portrait sketch, sometimes itty-bitty errors add up. In the case of the image below, the cumulative inaccuracies were bridged by the enormity of the young lady’s arm upon which her head lay. When I began the sketch, her head was gracefully touching the apex of her angled wrist. Had I followed through with this original pose, the forearm would not have been as extended.
I know this feeling. I recently redid a painting when my husband said the woman’s arm looked like a turkey leg and it did.