Hi,

Try like below

<odoo>
  <data>
    <!-- Inherit from existing report template -->
    <template id="report_saleorder_document_inherit" inherit_id="sale.report_saleorder_document">
      <!-- Add the second company logo -->
      <xpath expr="//div[@class='header']/table/tbody/tr/td[1]" position="after">
        <td style="text-align: right;">
          <img class="logo" t-if="doc.company_id.logo" t-att-src="get_logo_image(doc.company_id.logo)" width="200"/>
          <img class="second-logo" t-att-src="get_logo_image('your_module_name.static/src/img/second_company_logo.png')" width="200"/>
        </td>
      </xpath>
    </template>
  </data>
</odoo>

Regards