Reinforcing what others have said,
The catechism states that prayer is the raising of one’s mind and heart to God. So, we pray with that as the goal. If you find that looking at a picture assists you in achieving that internal state better, than that is fine, in fact preferable for you. Some things are more effective for others and neither is ‘the right way’. It is the goal that is important, not the external practises. Another may prefer to keep their eyes closed because it works better for them.
2559 "Prayer is the raising of one’s mind and heart to God or the requesting of good things from God."2 But when we pray, do we speak from the height of our pride and will, or “out of the depths” of a humble and contrite heart?3 He who humbles himself will be exalted;4 humility is the foundation of prayer, Only when we humbly acknowledge that "we do not know how to pray as we ought,"5 are we ready to receive freely the gift of prayer. "Man is a beggar before God."6
In fact, following some habit/practise/routine/words thinking that those are the goal or have some power in and of themselves is dangerous. If you make same errors during the rosary in following it’s form but truly raise your mind and heart to God you’re doing it right. If you obsessively focus on ensuring you make no mistakes in the form (number of prayers, right mysteries for the day, no slurring etc.) thinking that’s what makes the Rosary effective you are bordering on superstition. Our words have no special power over God.
2111 Superstition is the deviation of religious feeling and of the practices this feeling imposes. It can even affect the worship we offer the true God, e.g., when one attributes an importance in some way magical to certain practices otherwise lawful or necessary. To attribute the efficacy of prayers or of sacramental signs to their mere external performance, apart from the interior dispositions that they demand, is to fall into superstition.
And again, the catechism stresses that it is not the words that are important, they are tools to assist us in achieving that interior disposition for raising our heart’s and mind to God.
2562 Where does prayer come from? Whether prayer is expressed in words or gestures, it is the whole man who prays. But in naming the source of prayer, Scripture speaks sometimes of the soul or the spirit, but most often of the heart (more than a thousand times). According to Scripture, it is the heart that prays. If our heart is far from God, the words of prayer are in vain.