Magic of Ramda maybes

main.jsx

  createLogo() {
    R.compose(R.map(function (v) {
      return <img src={v}/>
    }), R.pluck('logo'), RF.Maybe);
  },
  defaultLogo() {
    return undefined;
  },
  render() {

    if (!this.data.loading) {
      return (
        <div className="ui container">
          <header style={this.style.header} className="ui centered grid">
            {this.createLogo(this.data.event).getOrElse(this.defaultLogo())}
          </header>
          {this.renderContent()}
        </div>
      )

Anyway, you need:
Compose(createDomForImg, Maybe(this.data.event).getOrElse(this.default))

That is called point free programMing