The degree of Ihsaan is beyond both Imaan and Islaam and is reserved only for the select and for the elect; those who are truly close to Allah سبحانه وتعالى.
They are those whose ibad’ah (worship), awareness of Allah عز وجل and ma’rifah (cognisance) of Allah is not just limited to ritualistic prayer or to ritualistic remembrance with the tongue. Rather, their belief, faith, and devotion to Allah rests securely in their hearts, and is reflected in their limbs and organs, in their external application of religion and most importantly it permeates their whole body and their very being.
So for them ihsaan (i.e. to worship Allah in a manner as though they see Him) is not just in the heart or the mind but their whole condition is one of ihsaan.
Truly that is a lofty degree to which all of us should aspire but we should realise at the same time that it is not easily gained and it requires determination, devotion, perseverance and sacrifice.