A Look That Says "there Will Be Consequences for This"
While some clinic visits are better than others, in the case of this kitty he is clearly unhappy to be there. Just about says it all; he would sooner be anywhere else in the world than on the test table being poked and prodded. He's being checked by the veterinarian for his own benefit, hence it's not his fault he just doesn't know it.
This kitten might resist if he were a bit larger, but given his small size, he seems to have accepted his fate.