from the linked document...
-------------------
What are the “official resources” to which this basic rule applies? Certainly the funds appropriated for Member, committee, and other House offices are official resources, as are the goods and services purchased with those funds. Accordingly, among the resources that generally may not be used for campaign or political purposes are congressional OFFICE EQUIPMENT (including the computers, telephones, and fax machines), OFFICE SUPPLIES (including official stationery and envelopes), and congressional STAFF TIME. (emphasis mine)
-------------------
The video is the result of authorized congressional efforts on behalf of the American public...and it is public knowledge. I have no doubt that Rep. Schiff is using campaign funding to distribute that public material...nonetheless, groundless opposition is to be expected...especially when a non-thinking, non-discerning audience will readily lap it up.
Link: https://ethics.house.gov/campaign/general-prohibition-against-using-official-resources-campaign-or-political-purposes