As for this kind of situation, you need to resort to Leawo iTransfer to manage your photos on iPhone. Just follow the below steps to do that.
is third-party software which allows you to transfer, delete or add files among iOS devices, iTunes and PCs. And it supports about 12 kind of files like app, music, movies, photo and so on. You can easily transfer, delete and add your photos, music or other types of files among those iOS devices. Let's take the details about how to delete photos on iPod as an example to see how it works.
1. Connect your iPod device to a computer;
2. Open Leawo iTransfer;
Open iTransfer and it will detect your iPod device automatically.
3. Find photos;
Click "Photos" which is in the contents of "LIBRARY" of iPod and then choose photos you want to delete on the right side of screen.
4. Delete photos
Right click to choose "Delete" button to complete the deletion after you selected those photos.
This way makes you easily delete photos on different versions of iPod nano, iPod touch, iPod Shuffle and iPod Classic as well as other iOS devices. If you don't mind that those photos on your iPod touch will be deleted from everywhere, you can choose the first way to delete them. In the second way, you need to find the folders which are synced with iPod nano first and then use iTunes to complete the deletion and it is no doubt that this is a complicated way. And about the third way-Leawo iTransfer, I think it is the most convenient way to realize the deletion compared with the former two ways. What do you think?
For more details, check: How to Delete Photos from iPod