To align images in Obsidian, a custom CSS snippet is needed. Once it is set, this allows you to center or right-align images while scaling the image size.

Step 1: Create a CSS snippet

1. Navigate to the snippets folder in your Obsidian Vault.
2. Create a new file called Image Align.css and add the following CSS code.

img[alt*="center"] {
    display: block;
    margin-left: auto;
    margin-right: auto;
}

img[alt*="right"] {
    float:right;
    clear:right;
    margin-left: 1rem;
    margin-bottom: 2px;
    margin-top: 2px;
}

Step 2: Activate the Snippet

1. Go to Settings → Appearance
2. Scroll down to CSS Snippet
3. Turn Image Align in the list ON.

Step 3: Insert an Align an Image

1. Insert an image
2. To specify alignment and sizer, modify the syntax as

![[picture name|center|350]]

• right or center: Aligns the image to the right or center.
• 100: Scales the image to 100 pixels in width.

Reference

https://forum.obsidian.md/t/align-image/78050