Drop down list data validation, coming from and object not a cell.

You can't do what you want with Data Validation but you can do this with Form Controls and Active X controls. Draw the shape or insert the object that you want, then select the Form Control or Active X control and add it to the shape. Select both shape and control and group.

The control is grouped with the shape. The shape is still only a shape and not a control. This is not like a clickable image used for some hyperlinks.

To resize the control and object together, click on the edge of the grouped objects, to select and resize using the sizing handles.

To resize the control without resizing the object, Ungroup the objects then right click in the edge of the control to select it. Select the sizing handle for the control and resize.