Images of Christ are sinful whether one is actively/directly worshipping it or not. As Thomas Vincent has said, "It is not lawful to have pictures of Jesus Christ, because his divine nature cannot be pictured at all; and because his body, as it is now glorified, cannot be pictured as it is; and because, if it do not stir up devotion, it is in vain"”if it do stir up devotion, it is a worshipping by an image or picture, and so a palpable breach of the second commandment."
The second commandment requires us, "according to each one´s place and calling, (to) remov(e) it, and all monuments of idolatry.[528]"
[528] Deuteronomy 7:5. But thus shall ye deal with them; ye shall destroy their altars, and break down their images, and cut down their groves, and burn their graven images with fire. Isaiah 30:22. Ye shall defile also the covering of thy graven images of silver, and the ornament of thy molten images of gold: thou shalt cast them away as a menstruous cloth; thou shalt say unto it, Get thee hence.
We may have no part in facilitating blatant idolatry, but we must also respect authority. A religious objection to posting an idolatrous picture put forth in a gracious and humble manner ought to be respected by a reasonable boss. If not, then there may be sacrifice required for the sake of Jesus, who teaches us not to make images of the Godhead (Rom. 1.23; Acts 17.29).
Praying for grace and wisdom, brother!