From what your pic looks to be then this is what is termed "productlisting" and as you have found and I suspect installed the column/grid module what is left is to define this as one column for display(versus 2 or 3) and this is in the admin > config > product listing ...BUT only if you have the module installed....

Then you may have to adjust the image size to be displayed
admin > config > images > image product listing > height & width and have an image availavble to suit