If you are looking for a "good guide" on how to handle these files or find more like them, here is how to navigate these specific assets:
955x1350 is a non-standard portrait aspect ratio. On sites like Wallhaven , you can filter specifically by this ratio to find mobile-optimized wallpapers or art intended for vertical displays.
For example, image hosting platforms like Wallhaven use specific resolution tags (955x1350) and unique ID strings to catalog portraits, such as popular fan art of characters like from Kaguya-sama: Love is War . How to use these strings effectively