Guessing because ideally there would be more context, but chances are this law firm is holding and managing monies in the interim, until such time as a final agreement is reached.

Example:
"Le compte séquestre permet, lors de la vente d’un fonds de commerce, de bloquer le prix de vente sur un compte spécifique. Ceci permet alors aux créanciers de se manifester dans un délai imparti et de réclamer les sommes dues. Une fois le séquestre levé, le vendeur peut récupérer les fonds disponibles. Le repreneur est alors totalement sécurisé vis-à-vis des créanciers."
https://www.msimond.fr/aide-contact/53/compte-sequestre-quel...

"An escrow agent is a third party, a person or entity, which holds an asset or funds before they are transferred from one party to another. The escrow agent holds the funds or the asset until both parties have fulfilled their contractual requirements."
https://www.google.com/search?q="escrow agent" glossary&sca_...

"Yes, a lawyer may act as both an escrow agent for all parties and a lawyer for one of the parties in the same transaction if all parties consent after full disclosure, as long as the lawyer is able to fulfill all of the lawyer’s duties to all parties under the escrow agreement without creating a conflict with the lawyer’s fulfillment of all ethical duties owed to the lawyer’s client in the transaction."
https://www.cobar.org/Portals/COBAR/Repository/ethicsOpinion...

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Note added at 2 hrs (2023-12-08 12:56:24 GMT)
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It has been said there is a UK/US divide in this matter. I cannot say I have encountered it. True, sometimes 'escrow agent' is defined as being the entity holding documents, but UK sources also use it for the organization holding monies, e.g.

http://www.escrowagent.co.uk/12.html
https://www.psgovernance.com/trusteeship/escrow-agent.html

In a field I am particularly familiar with (construction), we find:
"Under an escrow, the employer sets aside a sum of money in a ring-fenced account, managed by an escrow agent. The sum will typically equate to the maximum predicted spend in any two-month period during the works, to cover both certified monies and work in progress. If the employer fails to pay an amount due, the contractor – having given advance notice of his intention to do so – may draw on the escrow fund to make up the shortfall. The escrow agent may be a bank or a firm of solicitors, although many law firms are now reluctant to offer this service because of onerous anti-money laundering requirements. "
https://www.building.co.uk/comment/legal-the-benefits-of-esc...