Once you insert a picture in your slide, there is so much you can do it to make it appear consistent with the look of your slides — you can make corrections to brightness, sharpness, and contrast values. You can also play with recolor options, and apply Photoshop style filters. However, even before you play with all these options, you must ponder and decide whether you want to use PowerPoint’s Crop options. Cropping an area removes unrequired areas, and lets you add focus to the areas of the picture that are relevant to the topic of your presentation. Cropping also lets you remove some unwanted areas.
Learn how to work with simple crop options for pictures in PowerPoint 2011 for Mac.

