Display a picture from a url on mobile

Hi, 

I'm trying to do something I had hoped would be simple but that I can't get to work on mobile. 

I'm using nintex for O365.

The use case is to do with compliance on site where the initial form will include pictures being taken, and the task form to include the pictures visible so the manager can approve the work done. 

I'm trying to get the picture attachements from an item to be displayed on the task form. My workflow:

• Populate an item field with the url of the attachment
• Populate an item field with the url of the picture with <img src="URL"> 
• Upload the picture attachment in a document librairy on the same site and populate an item field with the url of the uploaded file

I've tried using the new responsive forms and the non responsive forms and the best I can get to is the image being displayed on a desktop but no luck with mobile. Both via a custom app and the generic nintex app.

i've tried using the image control, a calculated value, a page viewer, a label, and rich text. 

Is this simply not possible to do as of now? 

Thanks, 

Martin