Symptoms
K2 Icons missing in K2 Runtime whilst Designer displays them correctly.
Diagnoses
Smartform Runtime icons seem to be missing from the runtime location.
C:Program Files (x86)K2 blackpearlK2 smartforms RuntimeFiles - This did not have any PNG and GIF files for the icon.
C:Program Files (x86)K2 blackpearlK2 smartforms DesignerFiles - This has PNG and GIF files for the icon.
Resolution
Copied the missing files from Designer to Runtime file locations.
Ran IISREST after copying the files.
This should resolve the issue