A many to many has to be split up in two one to many.
For this you need a third table that comes 'in between' your two other tables, call it photoDVD_LineItem.
Make sure you have an ID (parent key) in both tables, photoID and DVDID. Those keys need to uniquely identify the records.
In your LineItem table you bring the two IDs together.
In your photo table: photoID
In you DVD table: DVDID
In your LineItem you have two fields: photoID_fk and DVDID_fk.
In the graph screen draw a line from
photoTable

hotoID to photoID_fk and from
DVDTable

VDID to DVDID_fk
When you look at the whole relationshipline you will see that the photos are related to the DVD, through your LineItem table.
Make records in the line item table for all the photos and all the DVD, where you show which photos are on which DVD.
You can make valuelist based on the fields in both tables for easy use.
Now you can put a portal in your DVD table, based on the LineItem relationship to show the related photos.