Understanding and application

Why do صَلَّى عَلَيَّ and صَلَّى اللَّهُ عَلَيْهِ convey different meanings in Hadith 206?

Salawat, Mosque Service, Good Character, and the Trust of Knowledge (Hadith 206–213)

• Allah is the subject in the first and a person in the second
• The first is a person sending salawat; the second describes Allah’s blessing
• Both concern building a mosque
• Neither expression conveys a meaningful idea