Reflection:

Perhaps Facebook was not the correct platform to choose for this experiment. My low participation on this platform means that even my normal posts garner relatively low numbers of "likes". This, paired with the seeming randomness of the outdated change, probably caused it to fly under the radar for most of my Facebook friends. 

I've also realized that the social media platforms I participate most in are ones where profile pictures are unimportant or absent altogether: Reddit, Steam, and Gmail. This may be a reflection of my friends' characters as well, since many people I regularly communicate with also do not actively post to Facebook. Therefore, it seems that those of us who gather outside of a particular form of social media won't receive strong feedback from others who actively participate.