I agree with Qatarisun. It's unfair to assume prejudice on the part of the employers in such cases in which they prefer one nationality over the other. In Qatar there are very good reasons for doing so--most notably immigration laws.

In terms of gender, the same holds true. No point in hiring men to clean a women's fitness area.

In terms of "good looking" requirements mentioned in other ads, I assume that's what the photo requirement is for.