Bulk Export Item Pictures in Business Central SaaS version as Zip File

 you can use the below code as it is for your test environment.

    Procedure DownloadItemImage()

    var

        MyItem: Record Item;

        TenantMedia: Record "Tenant Media";

        datacompresion: Codeunit 425;

        blobStorage: Codeunit "Temp Blob";

        PicInStream: InStream;

        ZipInStream: InStream;

        ZipOutStream: OutStream;

        ZipFileName: Text;

        ItemCnt: Integer;

        Index: Integer;

        PicCount: Integer;

    begin

        ZipFileName := 'Picture.zip';

        datacompresion.CreateZipArchive();

        MyItem.Reset();

        MyItem.FindSet();

        repeat

            if MyItem.Picture.Count > 0 then begin

                ItemCnt := ItemCnt + 1;

                for Index := 1 to MyItem.Picture.Count do begin

                    PicCount := PicCount + 1;

                    if TenantMedia.Get(MyItem.Picture.Item(Index)) then begin

                        TenantMedia.calcfields(Content);

                        if TenantMedia.Content.HasValue then begin

                            TenantMedia.Content.CreateInStream(PicInstream);

                            datacompresion.AddEntry(PicInStream, MyItem."No." + '.png');

                        end;

                    end;

                end;

            end;

        until MyItem.Next() = 0;

        Message('Items processed ' + Format(ItemCnt) + ' Pictures processed ' + Format(PicCount));

        blobStorage.CreateOutStream(ZipOutStream);

        datacompresion.SaveZipArchive(ZipOutStream);

        datacompresion.CloseZipArchive();

        blobStorage.CreateInStream(ZipInStream);

        DownloadFromStream(ZipInStream, 'Download zip file', '', '', ZipFileName);

    end;

This code simple create the steam of image media and add in zip archive

at last we download the full image file zip at once using DownloadFromSteam command