BuddyPress.org

@jende The avatars in the sidebar widgets are constrained down to 40px x 40px via stylesheet. The actual avatar size is 50px x 50px. You could change the avatar size via your bp-default child theme’s style.css file like so:
`#footer-widget-area div.item-avatar img, /* remove this line if you only want to change size in right sidebar */
div#sidebar div.item-avatar img {
height: 50px;
margin: 1px;
width: 50px;
}`