[kurapica.igas]

local infoSet = {
    infoFrame = {info1, info2, info3, info4},
    imageAnchor = {Image1, Image2, Image3, Image4},
    button = {button1, button2, button3, button4},
}
 
local function CreateInfoFrame()
    local i = #(infoSet.infoFrame) + 1
 
    local infoBox
    infoBox = CreateFrame("Frame")
    infoBox:SetSize(420, 90)
    infoBox:SetPoint("BOTTOMLEFT", infoSet.imageAnchor[i], "BOTTOMRIGHT", -12, 3.5)
    infoBox:SetFrameStrata("TOOLTIP")
    infoBox:SetFrameLevel("16")
    infoBox:SetBackdrop(Artwork_Import.infoBox)
 
    infoSet.infoFrame[i] = infoBox
    
    local button
    button = CreateFrame("Button")
    button:SetSize(80, 24)
    button:SetPoint("BOTTOMRIGHT", infoBox, "BOTTOMRIGHT", -12, 10)
    button:SetFrameStrata("TOOLTIP")
    button:SetFrameLevel("17")
    button:SetBackdrop(Artwork_Import.enableButton)
    button:SetBackdropBorderColor(0.2,0.2,0.2)
 
    infoSet.button[i] = button
 
    return infoBox
end
 
-- 1
local infoBox = CreateInfoFrame()
 
do
    infoBox.text = infoBox:CreateFontString(nil, "OVERLAY")
    infoBox.text:SetPoint("CENTER", infoBox, "CENTER")
    infoBox.text:SetFont(FONT, 10)
    infoBox.text:SetText(TEXT.BottomChat)
    infoBox.text:SetTextColor(classcolor.r, classcolor.g, classcolor.b)
end
 
-- 2
local infoBox = CreateInfoFrame()
 
do
    infoBox.text = infoBox:CreateFontString(nil, "OVERLAY")
    -- more
end

If you want create a things like template, you could create a factory function first, use it to create those infoboxs, don't know why you want using OnShow, just create those fontstring directly after you create each infobox should works ok