显示 BLOB 文件的 QSqlTableModel

有一个表格，其中除了通常的信息外，还以表格形式存储了PDF文档，BLOB以问号的形式显示如下：

如何让这些“问号”更人性化？（我想在那里放一些图标或其他东西，否则我立即期待用户的问题：“这些问号是什么？”）

最小示例（在代码文件旁边，您需要放置任何名为test_BLOB.jpg的文件，以便可以转换为BLOB）：

import sys
import os
from PySide2 import QtSql
from PySide2 import QtWidgets
from PySide2 import QtCore


class Storage_app(QtWidgets.QMainWindow):

    def __init__(self, parent=None) -> None:
        super().__init__()
        self.createConnection()
        self.fillTable()  # !!! тестовое заполнение базы данных
        self.createModel()
        self.initUI()

        self.centralWidget = QtWidgets.QWidget()
        self.setCentralWidget(self.centralWidget)
        layout = QtWidgets.QVBoxLayout(self.centralWidget)
        layout.addWidget(self.view)

        if not parent:
            self.show()

    def createConnection(self):
        self.db = QtSql.QSqlDatabase.addDatabase("QSQLITE")
        self.db.setDatabaseName("local_base.db")  # !!! .db
        if not self.db.open():
            print("Cannot establish a database connection")
            return False

    def fillTable(self):
        """
        Вспомогательная функция заполнениия базы данных
        Отключить после тестового запуска
        """
        file_path = (f"{os.getcwd()}\\test_BLOB.jpg")
        test_BLOB = self.convertToBinaryData(file_path)
        test_BLOB = QtCore.QByteArray(test_BLOB)

        self.db.transaction()
        q = QtSql.QSqlQuery()
        #
        q.exec_("DROP TABLE IF EXISTS company;")
        q.exec_("CREATE TABLE company ("
                "id INT PRIMARY KEY, "
                "name_company TEXT NOT NULL, "
                "blob_data BLOB NOT NULL );")

        # Вставка тестовых значений
        query = QtSql.QSqlQuery()
        query.prepare("INSERT INTO company (id, name_company, blob_data) "
                      "VALUES (:id, :name_company, :blob_data)")

        query.bindValue(":id", 1)
        query.bindValue(":name_company", 'АО КОПЫТА')
        query.bindValue(":blob_data", test_BLOB)
        query.exec_()

        query = QtSql.QSqlQuery()
        query.prepare("INSERT INTO company (id, name_company, blob_data) "
                      "VALUES (:id, :name_company, :blob_data)")

        query.bindValue(":id", 2)
        query.bindValue(":name_company", 'АО РОГА')
        query.bindValue(":blob_data", test_BLOB)
        query.exec_()

        self.db.commit()

    def createModel(self):
        """
        Создание модели для отображения
        """
        self.model = QtSql.QSqlRelationalTableModel()
        self.model.setTable("company")
        self.model.setHeaderData(0, QtCore.Qt.Horizontal, "id")
        self.model.setHeaderData(1, QtCore.Qt.Horizontal, "Наиманование")
        self.model.setHeaderData(2, QtCore.Qt.Horizontal, "Документы")
        self.model.select()

    def initUI(self):
        self.view = QtWidgets.QTableView()
        self.view.setModel(self.model)
        mode = QtWidgets.QAbstractItemView.SingleSelection
        self.view.setSelectionMode(mode)


    def closeEvent(self, event):
        if (self.db.open()):
            self.db.close()

    def convertToBinaryData(self, file_path):
        # Конвертирование в BLOB
        with open(file_path, 'rb') as file:
            blobData = file.read()
        return blobData


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    app.setStyle('Fusion')
    w = Storage_app()
    app.exec_()