Why cannot I put a picture into the shiny app through img()?

Question

My code is following:

ui <- fluidPage(
  titlePanel("My Shiny App"),
  sidebarLayout(
    sidebarPanel(
      h4("Installation"),
      p("Shiny is available on CRAN, so you can install it on the usual way from your R console:"),
      div("install packages('shiny')", style="color:red"),
      img(src="C:/Users/asus/Desktop/App-1/rstudio.png", height=70, width=200)
    ),
    mainPanel()
  )
)

The picture does not appear properly. Only an empty box appears where the picture should appear.