A little help please with the Vanishing Point tool

[Avi6C19]

Hello, I'm trying to use the Vanishing Point tool to paste a picture of a flower on the sides of the box.

This is the box: https://ibb.co/Rz65n06

This is the flower: https://ibb.co/qyDqtLM

This is the flowert combined with the box: https://ibb.co/KKs1Lbf 

Although I made sure the size of the images was good, for some reason the result is not sharp, the edges are not clear and Jagged , as you can see in the following example: https://ibb.co/PFwMVkR

Now I'm new to Photoshop, and I'm trying to design a result like this, so the picture looks like a 3D sticker outside the box. (I took this picture from another tutorial in the past): https://ibb.co/8rsYwB1

I would be happy and very grateful if anyone could help me solve the problem and briefly guide me in creating the desired design.

Sorry for my English, thanks in advance for the helpers.

[kevin stohlmeyer · Accepted solution]

What are your document image size settings - specifically the resolution?

If this is a small sized document at 72 ppi that would account for the "jagged" edges when applying the filter.

[Avi6C19]

Thanks for the help.

The main image is size: 1080x1080 at 72 ppi.

The image of the flower I want to paste inside the main image is size: 1024x768 at 72 ppi.

Do you think these sizes may be the reason for the "jagged" edges?

If so, in what way can I resize the image so that I can use this tool properly.

Thanks again 

[kevin stohlmeyer]

The linked graphic for the box you sent was significantly larger than this.

I would use that as your main image, do the Vanishing Point work, then downsample to the final size when complete.

[Avi6C19]

Thanks!! you were right. I just increased the resolution of the image and everything worked out. You helped me a lot thank you very much.