A serious contender
Although such discrimination can sometimes fall under the coverage of disability or religious discrimination laws, many cases do not and, setting aside all legal concerns, it is interesting to consider the extent to which subtle aspects come into play.
Would you be reluctant to hire a person because the individual is too good-looking?
Would a plain-looking or even ugly person get the job if the person's abilities exceeded those of any competitors or would they have to be far superior?
Can being well-dressed neutralize physical deficits? Is there a tendency to avoid extremes, such as a person who is a frump or a fashion-plate?
Is there an appearance blunder that triggers alarm bells? Can an otherwise fine candidate be done in by unshined shoes or a loud tie or scarf?
The more you delve into the topic, the more interesting it becomes.