and yet, and then, but, however, nevertheless
而 centers on a logical pivot: it marks a contrast or a sequential turn, like 'and yet', 'but', 'however', or 'and then'. The meanings all express a shift in thought, not a concrete object.
而 originally depicted a beard or whiskers, but its modern use as a grammatical particle is a phonetic loan. The character's form has been stable, but its meaning shifted entirely to function words.
The shape of 而 looks like a face with a long beard flowing down. Imagine a wise old man stroking his beard while saying 'and yet...' or 'but...', always adding a thoughtful twist.
For ジ, picture the old man with the beard (而) sipping a cup of tea (お茶, ちゃ) and saying 'and yet...' — the 'tea' sound is close to ジ, but to be precise, think of the letter 'G' as in 'Gee, and yet...' — the 'G' cues ジ.