This is a really excellent looking scene. I love all the little details you added in, from the clothing and ornamentation on each of the characters to the hoof fingernails. I'm captivated by how the unicorn is so docile looking while he's tied even though he looks like he could easily overpower both deer.
the expressions are provacative, the deer look like they are "admiring their prize", i mean they are hanging on him and gawking at him like a shiny new car and i cannot help but feel that they also treat him like an object, the unicorn has a distant look to him as if he is trying to ignore to events around him and retreat to his "happy place". my conclusion is he got caught up in some sort of slave trade
There is a lot of body language going on here and you have rendered it beautifully. Whatever is going on here there is nothing hostile in it the expressions and body posture of each creature say so. this is an awesome piece