Lua Code:
local frame = CreateFrame("Frame", nil, UIParent)
frame:SetSize(20, 20)
frame.Texture = frame:CreateTexture()
frame.Texture:SetAllPoints()
frame.Texture:SetTexture("Interface/Addons/YourAddon/YourImageFile")
frame:SetPoint("CENTER")
frame:Show() or frame:Hide() to show/hide as required