You are missing something big.  The size of the camera sensor is not mentioned. You need to know it, both in mm and in pixels.  You didn't say any sizes, but Samsung says 3.7 megapixels, so if 4:3, that is 2221 x 1666 pixels.  Samsung specs don't say. Your image will be this size though, you can know its pixel dimensions. 

The sensor mm is pretty difficult to determine on most phones. At most, the Samsung Note 4 says it is a 1/2.6" sensor, but this is a fake number, not a real dimension of anything.  Wikipedia says a Nokia 1/2.5" is 5.76 x	4.29 mm, but that's not real helpful. All we know though.

Not sure what you are trying to calculate, you seem to know both the size of the object and its distance.  The formula you found calculates distance, not size.  Here is a calculator that also computes distance, not size. 
http://www.scantips.com/lights/subjectdistance.html

Both require knowing sensor size, in mm and in pixels.
If you knew crop factor, the calculator can compute sensor size in mm.
I dare say this is is unknown too though.

Sensor height 4.29mm  
Focal length 4.8mm  
Sensor size 1667 pixels  
Subject size 596 pixels  
Subject height 0.9 meters  

Then Subject Distance 2.82 meters

So these numbers from plugging in your numbers and my guesses, it computes distance as 2.82 meters, which you said was 2.3 meters.  Seems halfway close, since we don't know the numbers.

This works better with bigger cameras for which we actually know specs.


EDIT:  Your detailed Exif helps.

It says 
Image Size : 5312x2988  
Megapixels : 15.9  
Focal Length : 4.8 mm (35 mm equivalent: 31.0 mm)

Not 3.7 megapixels anymore.  :)   And 5312x2988 is 1.78 aspect (HDTV).
So calculator says with camcorder crop factor of 31/4.8 = 6.48x (compared to 35mm film). We know the size of 35 mm, so using diagonals, it computes sensor height to necessarily be 5.84 mm height.

Other sources say Samsung 1/2.6" is 5.5x4.1 mm (4:3), close to Scott's numbers (but his is 1.44:1, which may be a typo?).  I am not aware of where Samsung says it.  However your image size says 5312x2988 which is 1.78:1 HD, camcorder mode. That wider image is necessarily shorter height. 

Anyway, from that, and corrected to portrait orientation, it computes sensor height (long dimension) as 5.84 mm and the distance computes 2.33 meters, using the numbers we can guess at.

http://www.scantips.com/g2/dist2.png