Diver's attraction or not the shadow looks like one long haired girl in a cap getting hugged by the other long haired one, whose cap falling off. My I guess it's Hibiki and Akatsuki. So yes, Heart-Warming.
The theme of the picture is "Thanks for Kantai Collection". Why? Because it brought the Akatsuki-class sisters back together!
Hibiki has been mourning her sisters since they sunk, leaving her alone to survive long after the war. In Kantai Collection their spirits are resurrected in human form, thus bringing them all back together again.
The picture emphasises the mourning Hibiki has been going through while showing them being reunited through the shadow in the corner. It's really heart warming, you guys! I'm holding back tears over here! :'(