Continuous attentiveness will only come with long practice. If you are truly watchful, each thought will dissolve at the moment that it appears. But to reach this level of disassociation you must have no attachments at all. If you have the slightest interest in any particular thought, it will evade your attentiveness, connect with other thoughts, and take over your mind for a few seconds. This will happen more easily if you are accustomed to reacting emotionally to a particular thought.
There is nothing wrong with looking at Bhagavan's picture. It is a very good practice. But you should not get sidetracked from your main objective, which is establishing yourself as consciousness. Don't get attached to states of bliss or give them priority over the quest for the Self.
If you can hold on to this knowledge 'I am Self' at all times, no further practice is necessary.