Good day folks.
I have a bottle as an object with the real height ($h_{\text{real}}$) is $13$ cm and I put the bottle in front of my recording video phone with varied distances between them as in the table below. The object and the recording phone are both on the same flat plain wall surface.
After I put the bottle in each distance variation, I measure the height of the displayed bottle in the video recording application's screen using my ruler as the table below listed. We call this displayed height ($h_{\text{displayed}}$).
So, we now have $3$ variables, real height ($h_{\text{real}}$), displayed height ($h_{\text{displayed}}$) and distance ($d$).
My quest is to find a formula that relates those $3$ variables. Below is the data that I acquired using measurement in the format of a table.
| distance ($d$) | height of the displayed object ($h_{displayed}$) |
|---|---|
| $3$ cm | $4$ cm |
| $4$ cm | $3.3$ cm |
| $5$ cm | $2.3$ cm |
| $6$ cm | $2$ cm |
| $7$ cm | $1.6$ cm |
| $8$ cm | $1.4$ cm |
| $9$ cm | $1.3$ cm |
| $10$ cm | $1.1$ cm |
| $11$ cm | $1$ cm |
| $12$ cm | $0.9$ cm |
| $13$ cm | $0.8$ cm |
| $14$ cm | $0.7$ cm |
And below is the graph to help you guess or estimate what the function is close to what function. It is like or similar or close to exponential function tough. 
Thank you for your help.
Best regards,
Me
To within the accuracy of the measurement it looks like the distance and display height are inversely proportional, where $d \cdot dh=11$. I didn't do a careful fit to get the $11$, just did it by eye off the data. The $11$ should be proportional to the height of the object. We can't be sure as you haven't tried different height objects.