I’ve fooled around with the optics required to see really small things, my experience is that you need at least a couple hundred dollars worth of glass to make this happen. The lens on a cell phone isn’t high enough quality to discern the details required for this type of work.
It is obvious that you just ‘fooled around’ with optics.
It is also obvious you didn’t read the article since they are getting 3D holograms from which they reconstruct high res 3D images.
It helps to read PRIOR to commenting.
Lurking’
When you look up at a clear blue sky and see the 'floaters' in your field of view, you are seeing the shadows of individual blood cells and other cellular debris inside your eye.
No lenses between them and your retina...
Ever hear of a "simple" microscope? The first microscope ever invented used a polished glass bead as the lens and produced sharp images at several hundred magnifications, although the image was dim due to a small aperature. The sample to be viewed had to nearly touch the lens, due to the short focal length. Today it would be a simple matter to install such a spheric lens above the sensor of a cell phone. A glass microsocpe slide could be laid directly onto the cell phone if the lens was recessed just a bit.