Dúvida no Ex. 5 da Aula 3 - Componentes ricos no formulário | Java e JSF 2 - II: Componentes ricos com Primefaces

o meu de remover e de editar não aparece o ícone correspondente fica um ícone com uma seta para cima.autor.xhtml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
    xmlns:h="http://xmlns.jcp.org/jsf/html"
    xmlns:f="http://xmlns.jcp.org/jsf/core"
    xmlns:p="http://primefaces.org/ui"
    xmlns:ui="http://xmlns.jcp.org/jsf/facelets">

<ui:composition template="_template.xhtml">

    <f:metadata>
        <f:viewParam name="autorId" value="#{autorBean.autorId}" />
        <f:viewAction action="#{autorBean.carregarAutorPelaId}"
            if="#{param.autorId != null}" />
    </f:metadata>

    <ui:define name="titulo">
        <p:outputPanel>Novo Autor</p:outputPanel>
    </ui:define>

    <ui:define name="conteudo">
        <h:form id="autor">
            <p:fieldset legend="Dados do Autor">
                <h:panelGrid columns="3">

                    <p:outputLabel value="Nome:" for="nome" />
                    <p:inputText id="nome" value="#{autorBean.autor.nome}"
                        required="true">
                        <f:validateLength minimum="5" />
                        <f:ajax event="blur" render="messageNome" />
                    </p:inputText>
                    <p:message for="nome" id="messageNome" />

                    <p:outputLabel value="Email:" for="email" />
                    <p:inputText id="email" value="#{autorBean.autor.email}"
                        required="true" validatorMessage="Email inválido">
                        <f:attribute name="type" value="email" />
                        <f:passThroughAttribute name="placeholder" value="Email do autor" />
                        <f:validateRegex pattern=".+@.+" />
                        <f:ajax event="blur" render="messageEmail" />
                    </p:inputText>

                    <p:message for="email" id="messageEmail" />

                    <p:commandButton value="Gravar" action="#{autorBean.gravar}"
                        process="@form" update="@form :formTabelaAutors" />
                </h:panelGrid>
            </p:fieldset>
        </h:form>

        <h:form id="formTabelaAutors">
            <p:dataList value="#{autorBean.autores}" var="autor"
                type="definition">
                <f:facet name="header">
                        Autores
                    </f:facet>

                <p:commandButton icon="fa fa-fw fa-edit" update=":autor">
                    <f:setPropertyActionListener value="#{autor}"
                        target="#{autorBean.autor}" />
                </p:commandButton>

                <p:commandButton icon="fa fa-fw fa-remove"
                    action="#{autorBean.remover(autor)}" update="@form" />

                    #{autor.nome} - #{autor.email}
                </p:dataList>
        </h:form>
    </ui:define>

</ui:composition>

</html>