PNG squares are clear squares that may seem round photos when they’re exported from Photoshop. They’re attributable to a setting in Photoshop that’s enabled by default. To do away with PNG squares, it is advisable disable this setting.
The setting that causes PNG squares is known as “Transparency Grid”. When this setting is enabled, Photoshop will add a grid of clear squares across the edges of photos when they’re exported as PNGs. This setting is meant to make it simpler to see the perimeters of clear photos, nevertheless it can be a nuisance.