Sentence:  The design of an indicator is often — indeed usually — thought to be the business of the engineer, perhaps aided by someone — an artist or a "stylist" — who adds an aesthetic touch, a <WSD>twiddly</WSD> bit, a strip of chromium, a dash of paint, or better still several dashes in clashing colours, of which a bilious yellow will be one. 
Meaning of the word marked with <WSD> tags:  Having an elaborately twisted form.