Perspective is one of those experiential things that sighted people seem to "just get." When you use technology such as the vOICe, or tactile graphics, things are a little harder since you are still learning how to see. If you don’t fancy using video glasses or don’t want to walk around to experience perspective, checkout the below link. It has pictures of frosted grass taken from various distances that get progressively closer. Try comparing the close ups with what you see using the zoom feature of the vOICe.