Solved
Dialog Image preview picker not displaying binoculars icon
not able to see preview icon(which looks like a binoculars) for browsing dam content(Images), only able to see edit and clear option. xml format is like below
<backicon
jcr:primaryType="nt:unstructured"
sling:resourceType="cq/gui/components/authoring/dialog/fileupload"
autoStart="{Boolean}false"
class="cq-droptarget"
fieldLabel="Back icon"
fileNameParameter="./fileNameBackIcon"
fileReferenceParameter="./fileReferenceBackIcon"
mimeTypes="[image]"
multiple="{Boolean}false"
name="./backicon"
title="Back icon"
uploadUrl="${suffix.path}"
useHTML5="{Boolean}true"/>
