Hey there,

I am really sorry for the delay of this reply as it is a public holiday for us here.

Can you try apply this following custom css into your site backend > Easyblog > theme > custom css and see how it goes.

@media (max-width:768px) {

#eb.mod-easyblogshowcase.is-mobile .eb-gallery-box {

    width: 400px !important;

}

}

if the issue still persists, can you update your site backend and FTP access at http://stackideas.com/dashboard/site so we can better have a check?