Bhagavad Gita · Raja Vidya Raja Guhya YogaChapter 9, Shloka 4 (9.4)

Shankaracharya — unattached. Avyakta-mūrtinā … karaṇa-gocara-svarūpeṇa — by a form that is not an object of the senses; na hi nirātmakaṃ kiñcit bhūtaṃ vyavahārāya avakalpate, ataḥ mat-sthāni — no being without a self can take part in the world's activity, so all are in me; but na ca ahaṃ teṣu … mūrtavat saṃśleṣābhāvena ākāśasyāpi antaratamo hi aham — because there is no clinging as with solid things, I am more inward than even space; na hi asaṃsargi vastu kvacit ādheya-bhāvena avasthitaṃ bhavati — what has no contact with anything is not "contained" anywhere.

Acharya Ramanuja — the inner controller. Mayā antaryāmiṇā tatam, asya jagato dhāraṇārthaṃ niyamanārthaṃ ca śeṣitvena vyāptam — I pervade it as the inner controller (antaryamin), as its master, in order to sustain and govern the world; evidence Brihadaranyaka 3.7 (yaḥ pṛthivyāṃ tiṣṭhan … yaṃ pṛthivī na veda); mat-sthāni sarva-bhūtāni … śarīratvena niyāmyatva-pratipādanāt — beings are governed by me as my body; na ca ahaṃ teṣu avasthitaḥ, ahaṃ tu na tad-āyatta-sthitiḥ, mat-sthitau taiḥ na kaścit upakāraḥ — my existence does not depend on them; I receive no benefit from them.

The difference: Shankara — non-attachment (untouched, like space); Ramanuja — the inner controller and ruler, who does not depend on the world that is his body.