Another type of red stem Philodendron (?) seemed to accidentally get put in the same pot with my Philodendron Birkin...does any one know what it is? Another photo in the comments. :
Araflora, exotic flora & more - Philodendron 'New Red'
Philodendron Red Emerald - The Curious Plantaholic
RARE Philodendron Florida Beauty Red Stem 4'' From - Etsy New Zealand