A picture gallery should have impact. It should be an attraction and not a distraction. It should show commitment to the space instead of appearing fickle, you kind of wanted to do one but this will do attitude. A picture gallery could take the place of anything as vast as a wallpaper or something as forward as an over-sized painting. It isn't in the background, yet it blends with the background while pulling the furniture pieces together much like an area rug would.
Take a look at the image below. I can't count how any times I've seen people hang dinky sized pictures in such a manner. In relation to the size of the furniture, those photos are doing anything but bringing balance to the space.
The correct way to do it would be as such: Imagine that the picture gallery is an area rug except it's on the wall. Better yet, imagine that the picture gallery is a reflection of the area rug being projected unto the wall. Like an area it should be properly scaled to accommodate the furniture in the space. When done this way it won't be lost in the furniture but will act as the anchor to the space.
There are many ways to put a picture gallery together, it's up to you the size of the photos and the quantity, but the scale should denote presence. Don't be afraid to hang them high (again, making the ceiling look taller), and don't be afraid of taking them lower than you normally would to extend the overall look of the space.
Below are some examples of ways to hang a picture gallery. Notice how large and impactful they appear in relation to the furniture.
Here are examples of picture galleries done right.
|Notice how this photo gallery almost looks like it's taking the place of wallpaper.|
|Here the photo gallery scales the entire wall, top to bottom, left to right.|
A picture/photo gallery is a statement piece, so let it make it's statement and good luck!