Remove the things on the walls and try some wallpaper. Something with a pattern. Can be bold for more drama or less depending on your style. Me personally would opt for a larger pattern to make a more, "wow" look. Try picking up a color in the paper and popping it up on the ceiling for an additional added detail. Replace mirror with a more interesting, stylish mirror. Be careful don't go too small with the mirror, marry it to the vanity for a more cohesive look. Finish with rug, towels and accessories to coordinate with the paper. If wallpaper is not in the budget try some coordinating horizontal stripes in neutral tones and pop some color on the ceiling. Get towels, rug and accessories to match accent ceiling color.

i agree with the other comments by Eye 4 Color! One other option would be painting the walls a dark color, which can actually open up a small space like this. And...consider painting that sink cabinet also --- whether you paint or paper the room. Painting the cabinet and changing the hardware to something more custom will really upgrade the room and take it out of the "box store" look! Leland

I think a slate blue type paint. Then, how about trying stenciling a design?

Great ideas!! I absolutely love this wallpaper. What do you think if I hang it in my powder room? Either as an accent wall with a light grey wall or on all four walls?

Jean. Love that wallpaper and what it would do for the small room, as others suggested. You could also dress up the mirror by having a frame/trim made to match the cabinetry. Also, I know it's a very small thing, but if you installed handles instead of those knobs on the vanity, you would be adding a vertical detail which would accent those full height doors and keep the details consistent. Best of luck and Have Fun! Cheers.

Jean, I love that wallpaper. Paint the vanity the dark, rich gray in the wallpaper and install 2 or 3 floating shelves over the toilet. Also consider painting the trim in the room white. Good luck.

This is nice

Jean, I love the wallpaper. Can you share any info about it? Thanks in advance!

Your wallpaper??

@jlgodshall. This is the info that I found about the wallpaper :-)
http://www.grahambrown.com/us/product/17605/Charming%20:%20Black%20Wallpaper

Bright paint, loved this color.

Thanks Keitha!

@jlgodshall. I am having difficulties finding the charming wallpaper by Graham & Brown in the black per the picture above anywhere online. Let me know if you have any luck at all.

Jean, what color is your granite? It appears to have dark green tones? How does the grey toned wallpaper work with your granite? Great ideas above; I would stick to paint on walls; cool wallpaper on the ceiling; crown molding, trim and vanity in white. New hardware on vanity; tall mirror and new lighting.