First obvious thing is the photo is that of brake pads and not a V brake.

Squeal from brakes is generally the pad/rim interface grabbing and letting go so fast that it is at a squeal frequency. The shape of the contact (is there pad toe in or out?), the condition of the pad and rim's surfaces (wet, dirty, glazed), The flexibility of the system (cables and hangers/stops, caliper pivots and arms, cable casing stuff all are suspects). And the rim/pad materials are all aspects that can add or reduce squeals.

The lack of the pads' releasing from the rim equally on both sides is usually a pivot friction or pivot spring tensions thing. Sometimes the casing can act as a spring action on one side only, pulling or pushing one arm in or out.

So many believe that extremely clean pads and rims won't squeal is quite wrong. The likely great friction can stress a less then ideal system and there will be squeal. I have quieted down brakes many times by rubbing garden soil on the pads to reduce their grabbiness. But the bottom line is whether the brakes consistently and reliably stop the bike. All else is only frustration. Andy