Distance between Two Praying Persons (Male/Female)
By obligatory caution, there should be a distance of — at least — one hand span between a man and a woman who are praying. In this case, their prayers are valid even if they are in the same row or she stands in front of him. However, in Masjid Al-ḥarām, it is not necessary to follow this caution.
 
Pictured Praying Mat & Engraved Turbah
To perform prayer on a prayer mat that has pictures on it or on clay [turbah] with engravings is not problematic in itself but if it provides an opportunity for those who accuse Shī‘ah, it will be obligatory to refrain from manufacturing such things and performing prayers on them. Also, if it entails absent mindedness and loss of concentration during prayer, it will be makrūh.

 To Pray while Music Is Played
 Staying in a place where forbidden music is being played is not permissible if it entails listening to the music. However, if someone says their prayer there, the prayer is considered valid.