IME defining actual height/width in px is best left to the dev which typically means hard-coding. Its difficult for anyone to remember exact h/w across variations.

What would a "generic" ACS Commons image component using this look like? Just pull the h/w vals from current style? Saving them to the component resource would just be the normal image component..

Lastly, while hard-coding width/height is quick, it feels like the design is seeping into component impl and may become brittle over time; this is actually what led to the idea for the Named Image Transform - which operates on a similar principle to CSS selector vs its style rules.

Also - is crop and height-based resize the big delta between this and the OOTB adaptive image component?