Does display of a defendant's body part (a foot) to the jury constitute testimony that subjects the defendant to cross-examination?

QUESTIONS PRESENTED 1. Does display of a defendant’s body part (a foot) to the jury constitute testimony that subjects the defendant to cross-examination? 2. Ina multi-defendant case, is it plain error for the court to repeatedly refer to the defendants as a single unit, especially where no instruction is given to treat each defendant individually? -2 List of All Proceedings 1. United States District Court, D.P.R., Docket No. 18-cr-00066-FAB; United States v. Figaro-Benjamin; judgment entered 12/2/2020. 2. United States Court of Appeals for the First Circuit, Docket Nos. 202129, 2183; United States v. Andino-Rodriguez; judgment entered 8/21/23. -3