With the exception of botanists, most people don't know the difference between the smaller types of oranges. As they all look the same i.e small, round and orange, i don't think pictures would help. We just have one name for thel big variety  (the one in your first picture) that is  "Orange". You could also call the smaller ones "orange" but people would probably call them "tangerines", "clementines", "satsumas", "mandarin oranges" etc - people aren't specific. use any of these words and people will understand you.