Gurfateh
All faiths have some symbols like Christians have Cross,Islam may have Cresent and Old Sanatan Dharm may have Om.
But often Shias use Allah as thier symbol,Some protestants may use verse from holy Bible hung.Hindus of Bajrang Dal use Trident(or Trishul).
We can have picture of Darbar Sahib,Verse of Gurbani in our house,Nishan Sahib or what is Called Khanda may have strong spritual or socail message in it.So it is Ok and OK is Ek Oankar also.Scocaily it may mean,Miri and Piri (Two Swrods)ie Spritual aspect is only usefull when it comes in practialc use via political force,But under one God(Khanda or sabre) and Circle represent it as eterneranl unededing and universal truth.
Anyway Picture depctiong old Sikhs or Gurus doing some work from which we can dervie inspiration are OK but at present often they are worshipped.
In the house of Das ,das had some pictures of Gurus but often Hindus and Turbaned Hindus insulted Gurmat by paying respect to them.So das tron them of or Burnt them.In one Gutka of Nanaksar Das had picture of Tenth Nanak,das tore it off.
So no need ot picture in present Kaliyuga as under mammon we our our coming genration may start to worship that.Give more emphsisi on Bani.