The phrase "abnormal appearance" refers to how someone or something looks different or unusual compared to what is considered normal or expected. Full definition
Urinary tract disease, including infection, abnormal frequency of urination, or abnormal appearance in urine color (cvm.ncsu.edu)
Of course, if discoloration or other abnormal appearances are observed, indicating contamination within the vial, it should be discarded. (prozinc.us)
Scar tissue also does not have any hair follicles associated with it, which is another factor that gives it an abnormal appearance from the rest of the skin. (sciencedaily.com)