General Support: Google indexing problem

Hi everyone,

Google image search dint index my plogger albums till recently, but with using the plogger sitemap my site started getting indexed by google image search. Now i have a problem here.
All my plogger images are getting indexed in google image search by the date uploaded. is there any possibility that i can make the image description(Alt text) be the first priority. here is my site's link in google image search.

If u see that link all the plogger images are indexed with the upload date.

Can anyone suggest a fix to this problem plz.