Yes. In Aperture, a regular Add Adjustment for something like Curves may only affect the active image, even if multiple photos are selected. To apply the same Curves settings to many images, use one of these workflows:

1. Create and apply a preset

   • Edit one photo with the Curves settings you want.
   • Save that edit as an Adjustment Preset.
   • Select all target photos.
   • Use Add Adjustment Preset to apply it to the whole selection.

2. Lift and Stamp adjustments

   • Make the Curves adjustment on one photo.
   • Right-click it and choose Lift Adjustments.
   • Select the images you want.
   • Right-click and choose Stamp Adjustments.

So the key point is: Add Adjustment and Add Adjustment Preset do not behave the same way for batch editing. If you want identical Curves settings on multiple photos, saving a preset or using Lift/Stamp is the reliable method.