Two UK researchers have reported that taking a photo each day and posting it online improves wellbeing in the form of "self-care, community interaction, and the potential for reminiscence."
Basically, looking for something different or interesting to photograph and post gets people to be more mindful and focus on positive aspects of their lives (since most of the posts are about positive things).
In some cases, it motivated people to get out and about so they could find something to photograph, which helped their fitness and increased the chances they'd interact with others.
If you're not into photography, posting a paragraph a day on social media or a blog might have the same effect. Of course, you could combine the two and write something personal about the photo and why it appeals to you or what it means to you.
Seems like something worth trying especially for writers; we tend to be introspective so maybe this is a safe little step outside our comfort zone!
And, just to practice what I'm preaching, here's a photo of the lovely not-so-young lady Sheridan and I were dog sitting today (we've both fallen for her):