One aspect addressed on this App is the intimidation people find from other gym goers staring at them whilst they train. This is equal for both men and women. In reality it is rare that people are actually interested in you. The 'gym poser' staring at you is not looking at you but seeing if you are looking at them! Otherwise what's the point in posing?
Another problem is body consciousness. Body consciousness is born largely from media hype and the perceptions they promote of the perfect male and female body. Not to mention the obsessive habits and diets they activity encourage.
It seems a little ironic that you need to go to a gym to gain a good body however, you have to go there for the most part before you attain it. When you attain the 'perfect body' and start feeling comfortable around others you no longer have to go!