Spanish has two terms for the word you: tu and usted. Tu is considered less formal, and usted is considered more formal. The specific Hispanic subculture dictates when and in which relationships to use one or the other. But in general, we use usted when speaking to older people to show respect. However, it establishes a sort of barrier or detachment between the two individuals because of the formality. Tu is more personable/casual and implies that the individuals are more socially close. If you want to clearly establish that you are having a respectful formal relationship with someone, use usted. If you want to clearly establish a casual social bond with someone, use tu. The post is then pointing out the dilemma of whether to show respect for their age by using usted or establish a romantic and intimate connection using tu.

Imagine if in English, we used thou to show respect and you to imply a laid back relationship. You'd probably use thou with grandparents, bosses, strangers in formal gatherings, etc., while using you with friends, siblings, romantic partners, etc. The dilemma would then be whether to use thou because she's an older lady or you because you want to not have any barriers preventing intimacy.