It has to do with the tire size on the PSS if you would have gotten ones with a smaller profile it would look less "bubbly"
The lower the middle number is the lower the profile while look
I am looking at tires currently because mine are overdue!
Example:
rears with 305/
35/19 will look thicker then 305/
30/19
hope this helps, but you should also note that they don't make every size so you need to check with the manufacturer to see what tires they have that will work with your rims