Sikh aesthetics have focused on music where the hymns of the Guru Granth Sahib Ji are played and sung. Guru Nanak Dev wrote over 900 hymns and in order for these to be used in worship, they are arranged as ragas or musical measurements so they can be sung to music.
Many people interpret the language of the Guru Granth Sahib symbolically since the Gurus have imposed layers of words on reality, demonstrating that language cannot directly approach the Real. For example, the term ‘Yamas’ has been used for the god of death and his minions which is found in Hinduism and Buddhism, but the name Azrael has also been used, who is the angel of death in Islam and is also mentioned in the Book of Tobit. A literalist might wonder what the ‘real’ name and nature of these beings that gather the dead actually is.
Sikhi rejects any form of idol worship including worship of pictures of the Gurus. One painting of Guru Tegh Bahadur can be dated to 1668 when he was painted at the court of Shaista Khan, governor of Bengal. The Guru was there on a peace-making mission between descendants of the princes who had been freed by Guru Hargobind from Gwalior Fort in 1619. However, no religious importance has ever been attached to this painting. Its importance lies in historical record rather than religion.
Other paintings of the Gurus are considered to be for educational or inspirational purposes only and are not regarded as objects of worship themselves.