Left and right aligned photos are a great option for your storytelling but sometimes your writing is much longer than the photo to accompany it.
The "Sticky" alignment options can make your photo sticky to the group as you scroll. This creates a very immersive effect for your visual story (as well as looking pretty cool). See below for an example.
Simple click "Sticky" from the Single Photo group options. "Top" is the default option if you want to reset the alignment.
The sticky effect will only be active if the writing is longer than the photo to accompany it. The feature is desktop only at this time.