Before Neos 2.0, the selectors for image width/height were visible by default. In Neos 2.0, this default has changed because we believe that people often go the “responsive-image” way. If you want to enable the selectors, add the following snippet to your
TYPO3: Neos: userInterface: inspector: dataTypes: 'TYPO3\Media\Domain\Model\ImageInterface': editorOptions: features: resize: TRUE
See all the options of the image editor in the documentation.