For such an imperfect picture (it has this scribbled look to it) it's absolutely perfect I love the shoes, the colours, their pose and of course Severus.
The art alone is beautiful, but then I started thinking abut who is tongue-tied and undeserving. Is this moment of utter trust and tenderness leaving Sev speechless or is he unable to express with words how much he loves him to an awake Harry? Does he feel undeserving of Harry's love or does he think Harry is undeserving of the welts - perhaps Harry's using pain as a way of dealing with the issues he cannot talk about?
And one more thing. Is Harry a creature? The blue hair and his ears and nose look suspiciously pointy. Are they mates?
Well, whatever the intent and story behind it, it's a wonderful piece of art - compliments to the artist :)