I've been to the DC and Oakland visitor centers, the sisters weren't especially beautiful. I know a few beautiful girls who got called to places like the Philippines for tracting missions. One thing I noticed was that 3/4 the sisters at the DC and Oakland temples were foreign. Maybe they want to send the all american beautiful ones overseas to recruit? I don't know. I also know some very beautiful "stake royalty" sisters who were sent to domestic, non-temple missions and SLC non-temple-square missions.
It would probably be really helpful for the missionaries at the DC temple to have foreign language skills. For one thing, DC is a very international city with all of the embassies that are located there. Also the temple is located in Montgomery County which takes in a huge number of immigrants from all over the globe.
When a sister puts in her papers she eventually has an interview with the Stake President .. he has her folder in front of him **INCLUDING A PHOTO ALBUM** OR PORTFOLIO ..He asks her about her preferences, talents and abilities .
The Stake President has already been briefed by the missionary commitee of the Church to be on the lookout for "Presentable sisters in high visibility locations ..
Of course intelligence and adaptability for languages and other criterea are also factored in..For instance the likeability for a certain type of sister in certain ethnic system is taken into account ..
Temple Square is the **Heaven on Earth** for all stunningly beautiful sisters followed by visitors centers at other temples
Don't know about the sisters but rumor has it Boyd Ky Packmehard likes to keep a portfolio of what he calls all the cute male missionaries. When it was pointed out to him that those aren't really missionaries but little boys with name tags that say missionary in training, he got really upset.
When you send in your mission papers, you have to also include a recent photograph of yourself, along with a health report that gives your height and weight. They probably discard the fatties, and then look at the pictures of the rest until they find the cuties. It is probably the one area of missionary assignments where the Big 15 really do still get personally involved. Since they grew up before internet porn, it probably also gets their little factories going. Well those whose little factories haven't shut down.