I've noticed in some of Hiiki's albums she capitalizes all the letters in a few songs like in Deep River she capitalizes SAKURAドロップス, DEEP RIVER, 東京 NIGHTS, and FINAL DISTANCE,

In Ultra Blue, BLUE, COLORS, and WINGS,

and in Heart Station HEART STATION.

I'm not sure if other Japanese artist do this, but it seems she most likely does this with a song that has the same name as the album i.e heart station, blue, deep river. and as for the ones that doesn't have the same title as the album is because those songs match the theme of the album, whatever it is I love that she does that. :)
Is there anyone who knows why she does this? any kind of interview she stated this? (you have to translate for me if an Japanese)
I'm just vary curious about this. also curious to why she only have done it with DEEP RIVER Ultra Blue and HEART STATION, and not First Love and Distance.