Custom style *should work roughly*

class.java

    public static class BigPictureStyle extends Style {
        private Bitmap mPicture;
        private Bitmap mBigLargeIcon;
        private boolean mBigLargeIconSet = false;

        public BigPictureStyle() {
        }

        public BigPictureStyle(Builder builder) {
            setBuilder(builder);
        }

        /**
         * Overrides ContentTitle in the big form of the template.
         * This defaults to the value passed to setContentTitle().
         */
        public BigPictureStyle setBigContentTitle(CharSequence title) {
            internalSetBigContentTitle(title);
            return this;
        }

        /**
         * Set the first line of text after the detail section in the big form of the template.
         */
        public BigPictureStyle setSummaryText(CharSequence cs) {
            internalSetSummaryText(cs);
            return this;
        }

        /**
         * Provide the bitmap to be used as the payload for the BigPicture notification.
         */
        public BigPictureStyle bigPicture(Bitmap b) {
            mPicture = b;
            return this;
        }

        /**
         * Override the large icon when the big notification is shown.
         */
        public BigPictureStyle bigLargeIcon(Bitmap b) {
            mBigLargeIconSet = true;
            mBigLargeIcon = b;
            return this;
        }

        private RemoteViews makeBigContentView() {
            RemoteViews contentView = getStandardView(R.layout.notification_template_big_picture);

            contentView.setImageViewBitmap(R.id.big_picture, mPicture);

            return contentView;
        }

        @Override
        public Notification build() {
            checkBuilder();
            Notification wip = mBuilder.build();
            if (mBigLargeIconSet ) {
                mBuilder.mLargeIcon = mBigLargeIcon;
            }
            wip.bigContentView = makeBigContentView();
            return wip;
        }
    }