<big>'''Real meaning of "δουλεία" in Greek:</big>
<big>Greek Word Study Tool:</big> δουλεία 1 n2 δουλεύω
I.servitude, slavery, bondage, Hdt., etc.
II.in collect. sense, the slaves, slave-class, id=Hdt.
Since Idol_latria means "Idolatry" or idol adoration/veneration/worship, IMAGE_DULIA (δούλεια) by the meaning above would mean IMAGE_bondage, or even IMAGE_SERVITUDE, which to me means that the ones that pay this kind of worship/honor/reverence to the image, has become its slave or servant.
Once we as Christians are servants of God because we worship/venerate/honor him, the Scriputes call us God's servants. In the same way, people become servants of these images because they worship/venerate/honor (pay dulia to them).
2Peter 2:19 While they promise them liberty, they themselves are the servants of corruption: for of whom a man is overcome, of the same is he brought in bondage.