why is it that When there is a small droplet on a phone the pixels of the screen can be seen

Given that the drop is small enough it produces a semi sphere on screen of liquid due to surface tension. This acts like a powerful convex lens for the light coming from pixels on the phone screen hence allowing the pixels to be seen by an observer due to this strong lensing effect. The lens is so powerful since the drop is so small hence a small radius which means it curves 'fast'. Hence the effect is so strong. When the drop is bigger the surface tension can no longer compensate for the weight of the drop and so drop becomes more flat like shape which takes away this curvature. Follow up question could be why surface tension causes drops to be sphere but this is likely beyond gcse required knowledge