One wearing a white outfit, all-pervading, glowing like the moon, having four hands, and having a pleasant face should be meditated upon to prevent any obstacles.
This small verse chanted before starting any important activity is supposed to remove obstacles and give success.
शुक्लाम्बरधरं विष्णुं शशिवर्णं चतुर्भुजम्
प्रसन्नवदनं ध्यायेत् सर्वविघ्नोपशान्तये ।।
శుక్లాంబరధరం విష్ణుం శశివర్ణం చతుర్భుజం
ప్రసన్నవదనం ధ్యాయేత్ సర్వవిఘ్నోపశాంతయే
What is it's significance?
Each word in the verse signifies something important-
White represents purity, calmness, freshness, openness, serenity and reduces stress, thereby allowing pure and fresh thoughts
All pervading nature assures that this power is everywhere and accessible from anywhere
Moon like glow indicates the cool rays which can cool down the heat of stress, and anxiety
Four arms are for protection from all the four directions
Pleasant face gives the positive mindset
Imagining this form is meant to inspire calmness, peace and joy allowing one to pursue any action with a positive mindset and thereby potentially avoiding obstacles and get success.