In touch UI, while authoring a page in a tablet, in image component , it is not possible to drag and drop an image from the content finder. Since the dialogs open in full screen mode in tablets, content finder is not visible and it is not possible to drag and drop image from content finder. The same behavior is also observed for we retail site for the image component - /apps/weretail/components/content/image
Is this the intended behavior, is the author not allowed to change the image from DAM in tablet authoring mode
Unlike desktop device, in mobile device such as tablet, the assets browser completely covers the page being edited. Hence to add an asset to your page, you will have to touch-and-hold the required asset, then move it towards the right - the assets browser will close to show the page again, where you can add the asset to the required component.
what you are saying is correct for dragging and dropping an image from asset finder, but when you need to drag and drop an image in the dialog tab of a component, then it is not possible to drop it from the asset finder , since the dialog is also open as full screen on the device(tablet)
in the image component, the sling resourcetype is set as -
then when the dialog is open, it is not possible to drag and drop an image form the asset finder since the dialog is open full screen. Hope you understand the predicament