I agree with both of you; they have a very valid argument; however my point was that this is done for female models - never male models, there is no discussion about the effects of male modelling on men's health issues (physical or psychological).
Oh btw, about the tipping - a nice study is available in full text
http://tippingresearch.com/uploads/TipAveJASP.pdf
Of interest which sums things up quite well is the tables at the very end of the piece. Note that the numbers represent the strength of the correlation
Table 1 shows that while average sales, physical attractiveness, service ability and self monitoring were more important than gender, sex was more important than friendliness.
(taken from table 1)
.96 Average Sales
.28 Self-Monitoring
.27 Physical Attractiveness
.27 Service Ability
.12 Sex
.10 Friendliness
.02 Service Experience
Table 2, shows a man's tips significantly depend on their sales and their service ability, then their self monitoring and finally with a very small correlation comes appearance. On the other hand for females while the other figures are similar, their service ability is vastly less important to the amount they are tipped, while their attractiveness is vastly more important.
(taken from Table 2)
WAITERS
.02 Physical Attractiveness
.49 Service Ability
WAITRESSES
.40 Physical Attractiveness
.19 Service Ability
Now just to make sure i have pointed this out clearly enough - their other figures were similar. these are merely the two categories in which there were substantive differences.
Also the sample size (51) was limited, but not so limited as to be something that can be readily dismissed.
edit: I would also point to this article
http://changingminds.org/techniques/tipping/articles/gender_tipping.htm but I cannot access the full text on which it is conclusions are based