diff --git a/components/image-preview.tsx b/components/image-preview.tsx
index da33459..1eeaacb 100644
--- a/components/image-preview.tsx
+++ b/components/image-preview.tsx
@@ -171,6 +171,11 @@ export function ImagePreview({
   };
 
   const { thumbnail, original, maxWidth, is4K } = parseImageUrls();
+  const preferOriginalForPreview = maxWidth >= 380 && original && original !== thumbnail;
+  const previewSrc = preferOriginalForPreview ? original : thumbnail;
+  const previewSrcSet = original
+    ? `${thumbnail} 1x, ${original} 2x`
+    : undefined;
 
   // 下载图片函数（下载原图）
   const handleDownload = async () => {
@@ -243,7 +248,8 @@ export function ImagePreview({
       {/* 缩略图（显示压缩后的缩略图）*/}
       <div className="group relative inline-block max-w-full mr-3 mb-3">
         <img
-          src={thumbnail}
+          src={previewSrc}
+          srcSet={previewSrcSet}
           alt="Generated Image"
           className="cursor-pointer rounded-lg transition-opacity hover:opacity-90"
           style={{ 
@@ -252,6 +258,8 @@ export function ImagePreview({
             width: "100%",
             objectFit: "contain"
           }}
+          loading="lazy"
+          decoding="async"
           onClick={() => setIsOpen(true)}
         />
         
diff --git a/components/multimodal-input.tsx b/components/multimodal-input.tsx
index 17ea135..36f5ad9 100644
--- a/components/multimodal-input.tsx
+++ b/components/multimodal-input.tsx
@@ -759,7 +759,7 @@ function PureMultimodalInput({
         className="rounded-xl border border-border bg-background p-3 shadow-xs transition-all duration-200 focus-within:border-border hover:border-muted-foreground/50"
         onSubmit={(event) => {
           event.preventDefault();
-          if (status !== "ready") {
+          if (status === "submitted" || status === "streaming") {
             toast.error("请等待模型返回当前回复后再继续");
           } else {
             submitForm();