Jerash- a preserved Roman city

Jerash is an amazingly preserved Roman city. It's 50km north of Amman. It's worth a trip. Like all the historic sites, it went through prominence to passage of heyday stages. The city rose to prominence from the time of Alexander the Great (333BC) and went down in 7th century AD. Most of the city have been well preserved till today. I luckily met a tour guide -Adam (a gentleman from California living in Amman) who was giving his friends a tour around Jerash. I happily joined the informative tour. After the tour, we had a healthy and delicious meal at a fabulous Lebanese restaurant. Lebanese food is considered high-end cuisine in Middle-East.
That evening, I decided to check out the famous trendy “Blue Fig Café” at the upscale district Abdoun. A glimpse of the modern and trendy café culture crowded by young and wealthy Ammanis where uncovered girls mingled with boys the same way as elsewhere in the world convinced me there's another Amman- referred to as Western Amman VS. Eastern Amman (a home to the poor, conservative and more Islamic in its sympathies). They are a world apart within 20km in one city under the same kingdom. The question is how one is decided to be in Eastern Amman or Western Amman? Are there double standards on these two very different crowds? Does Islam tell the Western Ammanis women that they don't have to cover their hair as long as they stay 20km away from the East side? I simply can't find a way to reconcile these two cultures in one city in one religion? Can they?