Add a button for the person completing to add photos

If the end users have Acrobat you can use this script:

this.importDataObject("Attachment1")

If they only have Reader you will have to create an attachment annotation first.  The following script test the whether the viewer is Reader.  If true it creates the annotation and triggers the attachment function.  If not it reverts to the previous script:

var nm;
if(app.viewerType=="Reader")
{
var num=1;
if(this.getAnnots())
{

var anot=this.getAnnots();
for(var i=0;i<anot.length;i++)
{
if(anot[i].type=="FileAttachment")
{num++}
}
}


var annot = this.addAnnot({
page: 0,
type: "FileAttachment",
name: "Attachment."+num,
author: "Attachment "+num,
rect: [0,0,0,0],
attachIcon: "Paperclip" });
annot.cAttachmentPath;
annot.hidden=true;

}
else
{
if(!this.dataObjects){nm=1}
else{nm=this.dataObjects.length+1}

this.importDataObject("MyFile"+nm);

}