From Xojo Documentation
If the Supports HiDPI setting in Shared Build Settings is set to OFF then pictures dragged into the project do not use the Image Set Editor and instead display as a single picture in the Picture Editor. Pictures added in this manner are not images and do not work well with HiDPI displays.
The Picture Editor can only be used with Desktop and Web projects.
The Picture Editor has zoom controls on the Command Bar and Transparent and Mask properties you can edit in the Inspector.