Displaying images on clicking tabs in flexdashboard using renderimage

Question

I took this code from stackoverflow In flexdashboard, can a valueBox be clicked to update a text box like an actionButton? (thank you!) and decided to tweak it to display images instead of text on click of button as follows:

    ---
    title: "valueBox Links"
    output: 
    flexdashboard::flex_dashboard:
    runtime: shiny
    ---

    ```{r setup, include=FALSE}
    library(flexdashboard)
    library(png)
    ```

    Tab 1 - Test
    ======================================================================

    
    Column 
    -------------------------------------

    #### Three valueBoxes

    ### valueBox 1
   ```{r}
   valueBox(1, caption = paste("I'm clickable!", actionButton("button1", " ", style = 
  "background-color:rgba(39, 128, 227, 0.0); border-color:rgba(39, 128, 227, 0.0); 
   position: 
   absolute; overflow: hidden; left: 0px; top: 0px; right: 0px; bottom: 0px; 
   width:100%")), 
   icon = "fa-thumbs-up", color = "success")
   ```

   ### valueBox 2
   ```{r}
   valueBox(2, caption = paste("I'm clickable too!", actionButton("button2", " ", style 
   = "background-color:rgba(39, 128, 227, 0.0); border-color:rgba(39, 128, 227, 0.0); 
   position: 
   absolute; overflow: hidden; left: 0px; top: 0px; right: 0px; bottom: 0px; 
   width:100%")), 
   icon = "fa-tag", color = "warning")
   ```

   ### valueBox 3
   ```{r}
   valueBox(3, caption = paste("ME TOO!", actionButton("button3", " ", style = 
   "background- color:rgba(0, 0, 0, 0.0); border-color:rgba(0, 0, 0, 0.0); position: 
   absolute; overflow: 
   hidden; left: 0px; top: 0px; right: 0px; bottom: 0px; width:100%")), icon = "fa- 
   random", color = "danger")
   ```

   Column
   -------------------------------------


   ### Image output
   ```{r}
   imageOutput("image", height = "100px")
   rv <- reactiveValues(data = NULL)

   observeEvent(input$button1, {
   rv$data <- readPNG('Picture1.png')
   })

   observeEvent(input$button2, {
   rv$data <- readPNG('Picture2.png')
   })

   observeEvent(input$button3, {
   rv$data <- readPNG('Picture3.png')
    }) 
   output$image <- renderImage({  
   rv$data
    })


    ```

What would be the change in my current code to display pictures on the click of different horizontal tabs? Thank you