A collection of Picture objects.
The PictureCollection.GetPicturesByName method allows you to obtain all pictures with the specified name in the collection. To find a picture by its unique ID, use the PictureCollection.GetPictureById method.
If a picture belongs to a shape group, it doesn't appear in the PictureCollection. To obtain such pictures, you can use the ShapeCollection.Flatten method of the Worksheet.Shapes collection. This method returns a collection of all drawing objects contained in a worksheet, including items of shape groups. Use the ShapeType property to filter this collection by type, as shown in the example below.
using System.Linq; // ... var pictures = worksheet.Shapes.Flatten() .Where(x => x.ShapeType == ShapeType.Picture) .Cast<Picture>();