I tacked this one myself on my site. This is a custom buddypress.org feature, and was all done by using firebug.
The Pointer you see in the borders for the avatars on the profiles is actually a background image, added to the border via CSS.
The Image that buddypress uses is https://buddypress.org/wp-content/themes/buddypress.org/images/av_speech.gif
Now you need to put the proper CSS in your theme’s global css.
`div.activity-avatar {
background: url( images/av_speech.gif ) top right no-repeat;
padding-right: 15px;
overflow: hidden;
width: 50px;
float: left;
margin-right: 10px;
}
div.activity-avatar img.avatar {
border: 4px solid #f0f0f0;
width: 40px;
height: 40px;
}`
Now since this is a custom CSS, you will need to tweak the rulesets to match your structure like changing the padding-right to how you like it, but the CSS here is a basic structure and will overall get it how you want it
I should make this into a quick tip 
What a quick tip on how to ‘Hot Link’ files? Are you sure that’s correct and proper? Google Hot Linking and stealing bandwidth!
Thanks @gunju2221! I added it and tweaked it and it worked fine 
@hnla, try penciling in a smile 
No, hnla you are right, I will upload the file to your own server and specify the file there.
My bad. I just can’t do anything right! 
@gunju2221 no please not to my server 
@julius38 the above merited a smile the former didn’t, though a grimace and frown might have been appropriate 
Yep! Quite restrained here on this forum though, you should see my antics on my other forum home 
for the record If I’m upset or feel real admonishment is necessary it will be very plain and clear I will always say so in no uncertain terms, the above wasn’t so it was gentle-ish chiding.