A few issues...
Your image is 360 × 600 pixels. The example image is 1000 × 1262 pixels. That is a fairly big difference in size. I'm not sure what mobile you're viewing your image on but most new smart phones have high pixel density screens—so what you think is a 360 × 600 pixel screen may actually be 720 × 1200 pixels or more.
Just so you can see the comparison, here are both images side by side at they're actual size:
So first thing; increase your image size.
Your type size is significantly smaller than the example. Compare your type size with the example and you can see you have probably double the number of words in a similar amount of space:
When you're working for print you can get away with 7 or 8 point type, but with the limited pixels of screens you want your type a fair amount larger than that; increase your type size.
Choice of Typeface
At small sizes especially, your choice of typeface makes a big impact on readability; in this case the difference in x-height is very noticeable.
Compare your text, which has a very low x-height (roughly 1/2 the ascender height)...
...against the example, which has a larger x-height (at least 2/3 the ascender height) with large bowls and counters—things that improve readability at small sizes:
A better typeface may be an option; if not—be aware of things like a small x-height and compensate by increasing the size accordingly.
Make everything bigger.