It is valid. Veneration is not directed to the physical representation but to the person.
We shall consider first the charge of idolatry, which the Iconoclasts brought against the Iconodules; then the positive value of icons as a means of instruction; and finally their doctrinal importance.
(1) The question of idolatry. When an Orthodox kisses an icon or prostrates himself before it, he is not guilty of idolatry. The icon is not an idol but a symbol; the veneration shown to images is directed, not towards stone, wood, and paint, but towards the person depicted. This had been pointed out some time before the Iconoclast controversy by Leontius of Neapolis (died about 650): We do not make obeisance to the nature of wood, but we revere and do obeisance to Him who was crucified on the Cross …
When the two beams of the Cross are joined together I adore the figure because of Christ who was crucified on the Cross, but if the beams are separated, I throw them away and burn them.’ Because icons are only symbols, Orthodox do not worship them, but reverence or venerate them. John of Damascus carefully distinguished between the relative honour of veneration shown to material symbols, and the worship due to God alone.
Saint John of Damascus orthodoxinfo.com/general/history2.aspx
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