For a good approximation of a gallery, try using a query set to "Custom". Select "Display Custom Data Templates" and use the "Thumbnail" Pre-Defined Template.
It's HTML and so you can play around with it. Here's some I tweaked from my app. {Picture} is just a Picture attribute in my BO - as is {PilotFirstName} and {PilotSurname}
<li class="aw-data-item" style="float:left;margin:5px;height:130px;width:110px;text-align:center;">
<div style="width:100px;height:75px;margin-left:15px">{Picture}</div>
<div><strong>{PilotFirstName} {PilotSurname}</strong></div>
</li>
This puts picture images in rows across the screen and works well on both mobiles and Desktops