The "team" pages in most investor pitch presentations and on most web sites are uninspiring. Some people have a picture, some have not. Some people wear a tie, others wear casual clothes. Some have a dark background, some light. Some pictures are taken from a distance, others are in close up. Some are cropped in 3:4, others manually.
Pictures and avatars are increasingly becoming your trade mark on the web. People do not have time to read names, and sometimes (in my case at least) most people are not able to pronounce it properly.
But why use individual pictures? The team and its ability to work together is one of the key assets an early startup has. At the next board meeting, get a good camera (or even better, a good photographer) in the room an take a group shot in a relaxed atmosphere. Stretch the image to a full page in PowerPoint and add arrows/name tags to point to these great people that are going to make this company a huge success.