Having a Catholic mother, I was force-fed that religion as a child, including 'holy pictures' of the 'saints.' I saw how easy it became for people to pray to these pictures and came to dislike them intensely.
Catholic 'saints' are most certainly not to be compared to our Gurus, but I have seen people pray to pictures of Guru Nanak Devi Ji, and it hurts me.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/sikh-gurus/14776-gurus-pictures-and-portraits.htmlReference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=14776
However, today I personally find pictures of the Gurus to be comforting, but I don't keep them around, except in the screensaver of my computer. I cannot imagine anyone praying to a computer screen!