Oh it's most certainly propaganda combined with karma farming. Ever notice how there is a steady steam of anti-trump content, contrasted with pleasant photos of Obama with a title harkening back to the good old days of his administration? You'll also notice that these posts get savaged in the comment section and yet still have 80% positive upvote ratings?
If you see something you suspect is propaganda on r/pics, just ask yourself, what is the user who submitted it trying to make me feel? What associations are they trying to form in my mind between the subject of the photo and the title?