There are many logic variations to displaying an issue constant's icon.

Such variations include:

• Checking if the image link is relative by checking if it starts with http:// and https:// and some just checks http://
• Some include the alt attribute
• Some include the title attribute with both name and description of the issue constant, some just has its name or none.

There is a velocity macro #macro(displayConstantIcon $constant) in plugins/jira which displays any issue constants icon.
All issue constant icons should use this macro to display the icon. (the macro will need to be updated after standardising the above variations)