This is the outcome of worship in solitude (ekanta seva). It is one of the nine types of devotion. Such devotees have the ability to sit in solitude in front of Swamiji’s photo and converse with Him internally. They get all their answers from Swamiji in their inner mind itself.
Such devotees do not talk directly to Swamiji or clarify their doubts face to face when they see Him. This is because Swamiji’s mind is constantly involved in various activities and hence keeps moving in different directions continuously. These devotees have not acquired the ability to unite their buddhi (intellect) with Swamiji’s mind that is relentlessly moving. Instead they realize that all their doubts are getting answered when they sit in front of Swamiji’s photo and worship it. Hence they do not exhibit any devotion in public or in Swamiji’s presence. Such bhakti is also nishchala bhakti (unflinching devotion). Swamiji loves to see such devotees.
-Glimpses of Bhaktimala 4