<li> <img data-interchange="[[[+image:pthumb=`w=720&h=288&zc=1`]], small], [[[+image:pthumb=`w=1600&h=640&zc=1`]], medium], [[[+image:pthumb=`w=2000&h=800&zc=1`]], large]" alt="[[+description:htmlentities]]" title="[[+description:htmlentities]]"> </li>
<li> <img data-interchange=", small], , medium], [/assets/components/phpthumbof/cache/roost-nowOpen-lrg.319cef30b1918f7719e868b41ade7db5.jpg, large]" alt="The Roost" title="The Roost"> </li>
This question has been answered by Bruno17. See the first response.
<img data-interchange="[ [[+image:pthumb=`w=720&h=288&zc=1`]], small], [ [[+image:pthumb=`w=1600&h=640&zc=1`]], medium], [ [[+image:pthumb=`w=2000&h=800&zc=1`]], large]" alt="[[+description:htmlentities]]" title="[[+description:htmlentities]]">
I think, the MODX-parser gets confused by this: [[[+image
try this:
<img data-interchange="[ [[+image:pthumb=`w=720&h=288&zc=1`]], small], [ [[+image:pthumb=`w=1600&h=640&zc=1`]], medium], [ [[+image:pthumb=`w=2000&h=800&zc=1`]], large]" alt="[[+description:htmlentities]]" title="[[+description:htmlentities]]">