Extracted from the website of Buddhist Vajrayana Charity Funds Association and translated (恭敬佛像功德) into English:

The Merits of Respecting Buddha Statues

Whenever one sees a Buddha statue, one must pay respect for; one must not even have a hint of blasphemy, and one must certainly not cause any damage to it. Should one place a Buddha statue on a bed or on the floor, one will have huge bad karma; should one step over a Buddha statue, one’s sin is even greater.

Why do we need to show respect for Buddha statues? It is because Buddha statues represent the Buddha Body. When we see a Buddha statue, we must remember the Buddha's merits and thus happiness arises in our heart. This is called a heart of reverence (a mind of reverence), or a heart of pure faith (a mind of pure faith). If one's heart has no respect, one will not have any merits. Hence, a heart of reverence (a mind of reverence) is the origin of all merits.

Sakyapa Gensang Zecheng Rinpoche discoursed on《The Immense Heart Essential》and said: “A person saw a small clay tower in the rain, quickly picked up some grass to cover it respectfully. Another person arrived, removed the dirt to replace with clean things respectfully. As a result, these two people with the merits of their actions, alongside the person who made the tower, all three became the Golden Wheel of the Wheel-Turning Kings.” As such, speaking and hearing names of the Three Jewels, or seeing Buddha statues or Buddha towers (stupas), can all become the Buddha seed.

A Buddha statue is the criteria for the achievement (attaining Enlightenment) of a Buddhist cultivator, it is also the reflective state for accumulating fortune of common people (sentient beings). Before this reflective state, we must all generate the right view, memorise all the merits of Buddhas, generate a heart of happiness, heart of reverence and heart of pure faith; and vow to cultivate, study and accomplish the Buddha Path. This is also the true meaning of creating Buddha statues by Buddhist disciples. Of course, for those people who do not possess a heart of reverence, Buddha statutes become the reflective state of creating karma.

Note: Besides Buddha statues, we must also have the same state of mind towards Buddhist sutras, Buddha towers (stupas), etc.