The law varies greatly among U.S. states, most of which treat this as a common law tort action rather than having a statute on point.
But, the question tags California, and under California law, the relevant statute, which is called the "Right of Publicity Law" is California Civil Code § 3344 (rights of publicity after you are dead are governed by parallel California Civil Code § 3344.1).
This statute, under the relevant circumstances, gives the person whose photos were used commercially without their consent the right to economic damages (but not less than statutory damages of $750), disgorgement of profits from the commercial use of the image, attorney fees, and sometimes punitive damages. In the case in the question, the economic damages are unlikely to exceed the $750 amount unless the employer is a massive chain of restaurants.
There are arguments that could be made against liability in this case, so it wouldn't be a sure recovery, but it would have a decedent chance of success.
The goal of the statute in this context is to have the employer separately pay a small fee, perhaps a few hundred bucks, to employees who serve as models for advertisements in addition to being employees doing their ordinary work. Of course, if your occupation is to be a promotional model (my wife's line of work for many years), your consent is inferred from the circumstances.
The statute states, in the pertinent part:
(a) Any person who knowingly uses another's name . . . photograph, or
likeness, in any manner, . . . for purposes of advertising or selling,
or soliciting purchases of, products, merchandise, goods or services,
without such person's prior consent, . . . shall be liable for any
damages sustained by the person or persons injured as a result
thereof. In addition, in any action brought under this section, the
person who violated the section shall be liable to the injured party
or parties in an amount equal to the greater of seven hundred fifty
dollars ($750) or the actual damages suffered by him or her as a
result of the unauthorized use, and any profits from the unauthorized
use that are attributable to the use and are not taken into account in
computing the actual damages. In establishing such profits, the
injured party or parties are required to present proof only of the
gross revenue attributable to such use, and the person who violated
this section is required to prove his or her deductible expenses.
Punitive damages may also be awarded to the injured party or parties.
The prevailing party in any action under this section shall also be
entitled to attorney's fees and costs.
(b) As used in this section, “photograph” means any photograph or
photographic reproduction, still or moving, or any videotape or live
television transmission, of any person, such that the person is
readily identifiable.
(1) A person shall be deemed to be readily identifiable from a
photograph when one who views the photograph with the naked eye can
reasonably determine that the person depicted in the photograph is the
same person who is complaining of its unauthorized use.
(2) If the photograph includes more than one person so
identifiable,then the person or persons complaining of the use shall
be represented as individuals rather than solely as members of a
definable group represented in the photograph. A definable group
includes, but is not limited to, the following examples: a crowd at
any sporting event, a crowd in any street or public building, the
audience at any theatrical or stage production, a glee club, or a
baseball team.
(3) A person or persons shall be considered to be represented as
members of a definable group if they are represented in the photograph
solely as a result of being present at the time the photograph was
taken and have not been singled out as individuals in any manner.
(c) Where a photograph or likeness of an employee of the person
using the photograph or likeness appearing in the advertisement or
other publication prepared by or in behalf of the user is only
incidental, and not essential, to the purpose of the publication in
which it appears, there shall arise a rebuttable presumption affecting
the burden of producing evidence that the failure to obtain the
consent of the employee was not a knowing use of the employee's
photograph or likeness.
(d) For purposes of this section, a use of a name, . . . photograph,
or likeness in connection with any news, public affairs, or sports
broadcast or account, or any political campaign, shall not constitute
a use for which consent is required under subdivision (a).
(e) The use of a name, . . . photograph, or likeness in a commercial
medium shall not constitute a use for which consent is required under
subdivision (a) solely because the material containing such use is
commercially sponsored or contains paid advertising. Rather it shall
be a question of fact whether or not the use of the person's name, . .
. photograph, or likeness was so directly connected with the
commercial sponsorship or with the paid advertising as to constitute a
use for which consent is required under subdivision (a).
(f) Nothing in this section shall apply to the owners or employees of
any medium used for advertising, including, but not limited to,
newspapers, magazines, radio and television networks and stations,
cable television systems, billboards, and transit ads, by whom any
advertisement or solicitation in violation of this section is
published or disseminated, unless it is established that such owners
or employees had knowledge of the unauthorized use of the person's
name, . . . photograph, or likeness as prohibited by this
section.
(g) The remedies provided for in this section are cumulative and shall
be in addition to any others provided for by law.
The most relevant language to this question is in bold.