When viewing them they remind us of our Gurus and their deeds
They act as an inspiration
They help as a visual aid when explaining Sikh history
They make it easier to remember Sikh history as a picture sticks to mind more than words.
However a lot of people have gone OTT and started worshiping pictures; like the Hindus worship an Idol.
Some people wake up and bow down to pictures.
Some people prepare prashad and stick it on the lips of the Guru on the pictures.
Some people get incense (doof) and wave it around a picture while doing paht
At Niskham Gurdwara (Soho road) some people bow down to a chair of past saints. (That is a form of idol worshiping)
When the Guru’s were in Human form Sikhs used to bow to the light of Guru Nanak that was present within all the Guru’s. Now Gurship has being given to Sri Guru Granth Sahib Ji a Sikh must only bow to Sri Guru Granth Sahib Ji. A real saint is full of humility and will not allow people to bow to him/her. A real saint puts all focus towards Sri Guru Granth Sahib Ji. Showing respect to elders by touching knees or feet is different but bowing down to others is a no go zone for a Sikh.
First Mehla:
The Hindus have forgotten the Primal Lord; they are going the wrong way
As Naarad instructed them, they are worshipping idols. They are blind and mute the blindest of the blind. The ignorant fools pick up stones and worship them. But when those stones themselves sink, who will carry you across? ANG 556 Sri Guru Granth Sahib Ji
Prabhaatee:
If the Lord Allah lives only in the mosque, then to whom does the rest of the world belong?
According to the Hindus, the Lord's Name abides in the idol, but there is no truth in either of these claims. O Allah, O Raam, I live by Your Name Please show mercy to me, O Master. ANG 1349 Sri Guru Granth Sahib Ji
Kabeer, some buy idols and worship them; in their stubborn-mindedness, they make pilgrimages to sacred shrines. They look at one another, and wear religious robes, but they are deluded and lost. ANG 1371 Sri Guru Granth Sahib Ji
Once there was a jatt (farmer), he was illiterate and had no knowledge of God or any form of education; he was made to believe that god was a stone. Dhanna ji put food in front of a stone, obviously a stone is not going to eat food. Seeing this Dhanna ji was upset as he thought God was upset. He decided not to eat until God had eaten the food. God showed himself through a stone to Bhai dhanna Ji. The sakhi is in Bhai Gurdas Ji’s vaars. I have written it below:
A brahman would worship gods (in the form of stone idols) where Dhanna used to graze his cow.
On seeing his worship, Dhanna asked the brahman what he was doing “Service to the Thakur (God) gives the desired fruit,” replied the brahman.
Dhanna requested, “O brahman, if you agree kindly give one to me.” The brahman rolled a stone, gave it to Dhanna and thus got rid of him.
Dhanna bathed the Thakur and offered him bread and buttermilk. With folded hands and falling at the feet of the stone he begged for his service to be accepted Dhanna said, “I will also not eat because how can I be happy if you are annoyed.”
(Seeing his true and loving devotion) God was forced to appear and eat his bread and buttermilk. In fact, innocence like that of Dhanna makes the sight of the Lord available
Sri Guru Arjan Dev Ji writes:
The Lord of the Universe met him personally; Dhanna was so very blessed. ANG 488 Sri Guru Granth Sahib Ji
Dhanna became a devotee of Sri Guru Arjan Dev Ji, His Bani was included in Sri Guru Granth Sahib Ji:
One Universal Creator God. By The Grace Of The True Guru:
I wandered through countless incarnations, but mind, body and wealth never remain stable.
Attached to, and stained by the poisons of sexual desire and greed, the mind has forgotten the jewel of the Lord.
The poisonous fruit seems sweet to the demented mind, which does not know the difference between good and evil.
Turning away from virtue, his love for other things increases, and he weaves again the web of birth and death.
He does not know the way to the Lord, who dwells within his heart; burning in the trap, he is caught by the noose of death.
Gathering the poisonous fruits, he fills his mind with them, and he forgets God, the Supreme Being, from his mind.
The Guru has given the wealth of spiritual wisdom; practicing meditation, the mind becomes one with Him.
Embracing loving devotional worship for the Lord, I have come to know peace; satisfied and satiated, I have been liberated.
One who is filled with the Divine Light, recognizes the undeceivable Lord God.
Dhanna has obtained the Lord, the Sustainer of the World, as his wealth; meeting the humble Saints, he merges in the Lord. ANG 487 Sri Guru Granth Sahib Ji