Two methods.....
1. Use the [DESCRIPTION_AND_IMAGES] tag and it works like any other precanned Auctiva template, i.e. you select the placement, grouping, etc. in the one-page lister.
2. Put two (or more) image tags side-by-side or use a table method and place the tags in separate cells. The later has some advantages with cell spacing/padding, etc. that might help overcome issues with varing picture sizes. Here's some simple starter code for this method:
<table cellspacing="4" cellpadding="1" width="100%" align="center" summary="" border="0"><tbody><tr><td>[IMAGE1]</td><td>[IMAGE2]</td></tr></tbody></table>
Hope that helps.
Danno