Normally this feature works for most of picture format, jpg extension included. The only bypass is on the definition of the picture.

Here is the default values:

  <extension target="org.nuxeo.ecm.platform.pictures.tiles.service.PictureTilingComponent"
    point="environment">
    <environment>
      <parameters>
        <!-- Image dimensions threshold tiling activation -->
        <parameter name="WidthThreshold">1200</parameter>
        <parameter name="HeightThreshold">1200</parameter>
      </parameters>
    </environment>
  </extension>

If you want to lowering the threshold contribute the previous xml fragment with your value in Advanced Settings > XML Extensions in studio.