My displays have been calibrated using a device called a Spectrophotometer to a gamma of 2.2. This is a precision instrument for calibrating color and brightness of either LCD or CRT displays as part of a fully color managed workflow. It insures that what I am seeing on the screen is going to be a good match to my prints, as well as providing a consistent standard to evaluate my work to for publishers, print labs, etc. For any photographer working in a digital darkroom - a spectrophotometer, or a simpler colorimeter should be considered must-have items. However, it does little to help those viewing this site have a display that may be off.
Not every monitor displays color the exact same, especially if it hasn't been calibrated. There may be some slight variations in what you are seeing on different computers. So there is a bit of a disadvantage for a photographer to display their work on the internet in that there is a certain lack of control over what you are seeing. I cannot control your monitor or its calibration obviously.
As a quick check on your monitor - you should be able to see all of the tonal graduations in this scale. If you can't, then you are not seeing an accurate representation of the images or prints that you may order. Laptops are notorious for displaying images too dark since less illumination preserves battery life.
You should adjust your contrast and brightness setting on your monitor (or laptop) to obtain as many distinct tones as possible. Please note that these adjustments are not a specific need for making our images appear better - it will make all sites you visit appear better! You may have not known what you've been missing if your monitor is really out of wack.
To adjust, this is done by setting your CONTRAST to its highest setting, and then adjusting BRIGHTNESS (higher or lower) to distinguish the range. The tones should also be neutral with no color casts. The difference between #12 and #13 is barely visible. In the image at the right, you should be able to see detail in the pines in the center of the image that do not have snow on them.
For further information on web browsers and color management, this page offers a lot of helpful advice and examples of how some monitors and browsers may not be showing accurate representations of artwork.