witness
臠 centers on witnessing or observing, with a possible extended sense of sliced meat (きりみ) that may relate to seeing something cut or presented.
The historical origin of 臠 is uncertain. It combines 䜌 (a complex component associated with binding or connecting) with 肉 (flesh/meat), but how this yields the meaning 'witness' is unclear. The kun reading きりみ (sliced meat) suggests a possible original meaning related to cut meat, with 'witness' perhaps a later extension.
The top part 䜌 looks like tangled threads or words, and the bottom is 肉 (meat). Imagine a witness untangling a messy story while looking at a piece of meat as evidence.
For レン, picture a witness in a courtroom pointing at a lens (レンズ) that captured the crime: lens -> レン, and the witness saw it clearly.