To like another users' photo in Photo Feed:
Navigate to "Explore" button in bottom navigation menu
Tap "Photo Feed" in the top right hand corner
Scroll through the photo feed and find the photo(s) you would like to heart
Tap the heart icon
You have now successfully liked a users' photo
*Note: You cannot comment on users' photos. If that changes we will update this article with information on how to comment on users' photos.