Wiring for Bathroom Lights

I want to install a smart light switch to control the ceiling-mounted LED bulbs in my bathroom. I was hoping to use an Aqara D1 or H1, as I have elsewhere in the house, but can’t figure out the wiring to do so.

The current light switch is using a double pole switch (wiring shown below), although I don’t know why – is this standard practice for bathroom light switches?

I can’t figure out the correct wiring – how does the existing wiring relate to the Live, and Switched Live (neutral not required) needed for the smart switch? I can get power to the switch (and connect it to HA), but it will not control the lights.