Hi,
I am sorry, but description of your issue is too vague. I need more information to be able to give you appropriate advice.
Could you please write me which version of Kentico
CMS are you using?
Are you using workflow?
What kind of web parts are placed on master page and what kind of web parts are used to display to the images?
Where are these images stored?
Could you please also write me type of these images?
Moreover, have you tried to display the images on other pages or just on master page?
Best regards,
Michal Legen