After inserting a video within your presentation, you may see a blank/black rectangle instead—caused by the file format of the video clip inserted on the slide. Not all the formats show these blank/black rectangles. In fact, you may also see the first frame of the video clip in some cases. However, if you do see this blank/black rectangle, do note that it may look professional. With PowerPoint’s Poster Frame option, you can easily overcome this limitation, and change the black rectangle to a picture of your choice by selecting a frame from the video itself, or even a picture from a different source.