That's just so amazing. It really caught my eye. To me, it looked like a part of a movie or something. I love those expressions, too. And it's oh-so-cute! ANd also, it really looked like a painting. To think that this is digital... o_0 It... it's really crazy! XD Well, I must say that I'll be looking up to you and your art work, *colonel-strawberry! I really hope to be as good as you someday!

And yes, those expressions..! Truly beautiful. I don't know, I guess you're just yoo good with the facial expressions, because whenever I draw facial expressions... It's just not this good. I think that the fact that the two are mangy mutts, it makes the faces look amazing. Good choice, technique.. and facial expressions!

This is a really wonderful piece, for many reasons, and with few improvements to be made.

The detailing in the characters is clearly very attentive work, and does look quite realistic. The design of the characters is excellent, as their features are a perfect balance of humanoid and animal; their clothing is very realistic, and interacts properly with the characters - it sits properly on them, and digs in where it needs to (like the collar, for example).

The background does seem like a bit of a cop out, but I only really noticed it because your description drew attention to it. The simplest way to do a background is just what you did - oick a vague sort of wall and make it blurry. But it isn't so terribly difficult to pick a slightly more interesting setting, like a library, or a billiard room, and paint that. It isn't necessary to lay out an entire room in detail and show perspective and depth - a single wall is fine - but it helps to know exactly where they are, even if it is as an afterthought.

As for realism, many would say you've achieved a perfectly acceptable level of it. However, here are some ways of increasing that realism;
Firstly, watch your edges. Every edge of dog fur needs to look like dog fur, with individual strands sticking out. In fact, you could show more individual strands in general on your characters.
Also, in some places it almost looks like there are traces of lineart - around Fig's nose, for example. This makes her look flat, and detracts from the realism in other parts of the picture.
Your lighting is pretty good with Jasper, as it lights up individual hairs, and all the lighting seems to be coming from the same place. Unfortunately, his ears do not seem to be lit quite as well as the rest of him. Equally unfortunately, Fig doesn't seem to have quite the same attentive lighting. This is one case where it helps to have a good idea of where they are, so you can choose a good, solid light source, and maybe even a secondary light source, for interest.
And finally, the eyes. One of the first and foremost sources of realism for a character is in the eyes. They need a little more depth and detail (lines in the iris, maybe just a touch more shadow for definition), and definitely that little shine that shows the whole eye is an orb, and not just the iris.

I still believe that this is a great picture, and your style is very clear. Good luck in your future endeavors - I'm sure they will be fantastic!