What is considered unduly prejudicial evidence in a civil case?

result, evidence should be excluded as unduly prejudicial "'when it is of such nature as to inflame the emotions of the jury, motivating [jurors] to use the information, not to logically evaluate the point upon which it is relevant, but to reward or punish one side because of the jurors' emotional reaction. In such a circumstance, the evidence is unduly prejudicial because of the substantial likelihood the jury will use it for an illegitimate purpose.' [Citation.]" (People v. Escudero, supra, 183 Cal.App.4th at p. 310.)